SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 424 
WHERE 
  cscart_products_categories.product_id IN (
    3925, 
    2807, 
    3415, 
    2612, 
    3077, 
    3409, 
    3411, 
    3413, 
    3550, 
    3878, 
    3515, 
    3875, 
    2926, 
    3748, 
    3128, 
    2543, 
    3288, 
    3035, 
    3220, 
    3410, 
    3599, 
    5107, 
    6112, 
    3043, 
    3880, 
    2429, 
    3805, 
    2921, 
    3095, 
    3524, 
    3742, 
    3668, 
    3044, 
    3168, 
    3527, 
    3535, 
    3360, 
    3702, 
    3536, 
    3101, 
    3167, 
    3750, 
    3830, 
    3592, 
    3670, 
    3684, 
    3600, 
    3874, 
    3365, 
    3437, 
    3682, 
    3879, 
    3753, 
    2952, 
    3230, 
    3108, 
    3303, 
    3376, 
    3412, 
    3436, 
    3554, 
    5104, 
    3103, 
    3530, 
    3945, 
    3438, 
    3545, 
    3555, 
    5895, 
    5868, 
    3687, 
    3860, 
    3858, 
    3853, 
    3857, 
    3863, 
    3862, 
    3854, 
    3727, 
    3699, 
    3855, 
    3859, 
    5105, 
    8812, 
    6163, 
    6853, 
    6161, 
    7807, 
    6062, 
    6854, 
    6060, 
    6061, 
    7823, 
    7838, 
    7827, 
    6821, 
    7829, 
    7811, 
    7866, 
    10103, 
    6852, 
    7841, 
    6850, 
    6855, 
    7856, 
    7861, 
    10160, 
    7863, 
    7840, 
    7812, 
    7855, 
    7860, 
    7868, 
    7869, 
    7870, 
    10242, 
    7813, 
    7825, 
    8242, 
    8373, 
    8517, 
    8700, 
    10246, 
    7837, 
    7864, 
    8285, 
    8287, 
    8330, 
    8374, 
    8571, 
    8726, 
    8728, 
    8803, 
    10085, 
    10099, 
    10106, 
    10256, 
    7859, 
    8268, 
    8331, 
    8378, 
    8436, 
    8442, 
    8579, 
    8583, 
    8606, 
    8727, 
    10107, 
    10166, 
    7858, 
    7862, 
    8270, 
    8286, 
    8376, 
    8384, 
    8402, 
    8467, 
    8468, 
    8531, 
    8533
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00863

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "339.21"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 366,
            "rows_produced_per_join": 366,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (3925,2807,3415,2612,3077,3409,3411,3413,3550,3878,3515,3875,2926,3748,3128,2543,3288,3035,3220,3410,3599,5107,6112,3043,3880,2429,3805,2921,3095,3524,3742,3668,3044,3168,3527,3535,3360,3702,3536,3101,3167,3750,3830,3592,3670,3684,3600,3874,3365,3437,3682,3879,3753,2952,3230,3108,3303,3376,3412,3436,3554,5104,3103,3530,3945,3438,3545,3555,5895,5868,3687,3860,3858,3853,3857,3863,3862,3854,3727,3699,3855,3859,5105,8812,6163,6853,6161,7807,6062,6854,6060,6061,7823,7838,7827,6821,7829,7811,7866,10103,6852,7841,6850,6855,7856,7861,10160,7863,7840,7812,7855,7860,7868,7869,7870,10242,7813,7825,8242,8373,8517,8700,10246,7837,7864,8285,8287,8330,8374,8571,8726,8728,8803,10085,10099,10106,10256,7859,8268,8331,8378,8436,8442,8579,8583,8606,8727,10107,10166,7858,7862,8270,8286,8376,8384,8402,8467,8468,8531,8533))",
            "cost_info": {
              "read_cost": "168.11",
              "eval_cost": "36.60",
              "prefix_cost": "204.71",
              "data_read_per_join": "5K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "softwarepirmam_hewadelivard_cscart_4.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 18,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "91.50",
              "eval_cost": "1.83",
              "prefix_cost": "332.81",
              "data_read_per_join": "57K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`storefront_id` in (0,1)) and ((`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`usergroup_ids`))) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`status` in ('A','H')))"
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "softwarepirmam_hewadelivard_cscart_4.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 18,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "4.58",
              "eval_cost": "1.83",
              "prefix_cost": "339.22",
              "data_read_per_join": "292"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}