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 
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') 
WHERE 
  cscart_products_categories.product_id IN (
    908, 
    134, 
    1142, 
    853, 
    1146, 
    1145, 
    1144, 
    1143, 
    856, 
    1540, 
    1541, 
    1542, 
    1543, 
    1544, 
    1545, 
    2258, 
    2257, 
    2256, 
    2255, 
    2260, 
    2259, 
    2251, 
    2262, 
    2261, 
    2252, 
    2265, 
    2264, 
    2263, 
    2253, 
    2267, 
    2266, 
    2254, 
    2559, 
    2560, 
    3663, 
    2562, 
    2729, 
    2730, 
    2731, 
    2732, 
    2746, 
    2747, 
    2749, 
    2750, 
    2751, 
    2752, 
    2753, 
    2754, 
    2755, 
    2756, 
    2757, 
    2768, 
    2767, 
    2775, 
    2786, 
    2787, 
    2788, 
    2789, 
    2790, 
    2791, 
    2792, 
    2793, 
    2794, 
    2795, 
    2796, 
    2800, 
    2801, 
    2822, 
    2823, 
    2824, 
    2825, 
    2826, 
    2860, 
    2869, 
    2870, 
    2871, 
    2877, 
    2878, 
    2879, 
    2880, 
    2881, 
    2927, 
    2928, 
    2929, 
    2935, 
    2936, 
    3011, 
    3012, 
    3013, 
    3014, 
    3015, 
    3021, 
    3022, 
    3023, 
    3024, 
    3026, 
    3030, 
    3029, 
    3060, 
    3061, 
    3090, 
    3091, 
    3092, 
    3093, 
    3094, 
    3099, 
    3100, 
    3140, 
    3141, 
    3160, 
    3161, 
    2760, 
    3164, 
    3165, 
    3366, 
    3367, 
    3404, 
    3405, 
    3548, 
    3549, 
    3373, 
    4124, 
    4125, 
    5129, 
    5126, 
    5135, 
    5133, 
    5151, 
    5153, 
    7871, 
    7872, 
    7873, 
    7875, 
    7876, 
    7874, 
    7877, 
    8703, 
    8704, 
    8705, 
    8706, 
    10454, 
    10455
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00531

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "299.51"
    },
    "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": 330,
            "rows_produced_per_join": 330,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (908,134,1142,853,1146,1145,1144,1143,856,1540,1541,1542,1543,1544,1545,2258,2257,2256,2255,2260,2259,2251,2262,2261,2252,2265,2264,2263,2253,2267,2266,2254,2559,2560,3663,2562,2729,2730,2731,2732,2746,2747,2749,2750,2751,2752,2753,2754,2755,2756,2757,2768,2767,2775,2786,2787,2788,2789,2790,2791,2792,2793,2794,2795,2796,2800,2801,2822,2823,2824,2825,2826,2860,2869,2870,2871,2877,2878,2879,2880,2881,2927,2928,2929,2935,2936,3011,3012,3013,3014,3015,3021,3022,3023,3024,3026,3030,3029,3060,3061,3090,3091,3092,3093,3094,3099,3100,3140,3141,3160,3161,2760,3164,3165,3366,3367,3404,3405,3548,3549,3373,4124,4125,5129,5126,5135,5133,5151,5153,7871,7872,7873,7875,7876,7874,7877,8703,8704,8705,8706,10454,10455))",
            "cost_info": {
              "read_cost": "151.01",
              "eval_cost": "33.00",
              "prefix_cost": "184.01",
              "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": 16,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "82.50",
              "eval_cost": "1.65",
              "prefix_cost": "299.51",
              "data_read_per_join": "51K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}