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 (
    3564, 3482, 3581, 3574, 3583, 3579, 3476, 
    3569, 3870, 3562, 3543, 3856, 3585, 
    3503, 3488, 2119, 3577, 3899, 3544, 
    3502, 3823, 3884, 3575, 3539, 3541, 
    2120, 3576, 3469, 3584, 3487, 3808, 
    3868, 3472, 3514, 3580, 3473, 3479, 
    3572, 3866, 3570, 3582, 3489, 3567, 
    3861, 3561, 3504, 3475, 3565, 3573, 
    3568, 3563, 3547, 3513, 3586, 3542, 
    3571, 3566, 3474, 3538, 3540, 3587
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00319

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "134.46"
    },
    "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": 149,
            "rows_produced_per_join": 149,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (3564,3482,3581,3574,3583,3579,3476,3569,3870,3562,3543,3856,3585,3503,3488,2119,3577,3899,3544,3502,3823,3884,3575,3539,3541,2120,3576,3469,3584,3487,3808,3868,3472,3514,3580,3473,3479,3572,3866,3570,3582,3489,3567,3861,3561,3504,3475,3565,3573,3568,3563,3547,3513,3586,3542,3571,3566,3474,3538,3540,3587))",
            "cost_info": {
              "read_cost": "67.41",
              "eval_cost": "14.90",
              "prefix_cost": "82.31",
              "data_read_per_join": "2K"
            },
            "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": 7,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "37.25",
              "eval_cost": "0.75",
              "prefix_cost": "134.46",
              "data_read_per_join": "23K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}