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 (
    9743, 10015, 10017, 9721, 9748, 9906, 
    10018, 10331, 10019, 10338, 9761, 10001, 
    9752, 10362, 9722, 9745, 10337, 10000, 
    9746, 10002, 9720, 9998, 10003, 9755, 
    9995, 9999, 9763, 9912, 10342, 9911, 
    9992, 10014, 10306, 10334, 9900, 10330, 
    9910, 10301, 9759, 9905, 10300, 10304, 
    10307, 10308, 10332, 10340, 9750, 9867, 
    10302, 10333, 10336, 10341, 10343, 
    10363, 9757, 9902, 9908, 9984, 9990, 
    10016, 10305, 10329, 10335, 10339, 
    9873, 9891, 9889, 9893, 9987, 10303, 
    9896, 9899, 9986
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00174

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "77.46"
    },
    "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": 74,
            "rows_produced_per_join": 74,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (9743,10015,10017,9721,9748,9906,10018,10331,10019,10338,9761,10001,9752,10362,9722,9745,10337,10000,9746,10002,9720,9998,10003,9755,9995,9999,9763,9912,10342,9911,9992,10014,10306,10334,9900,10330,9910,10301,9759,9905,10300,10304,10307,10308,10332,10340,9750,9867,10302,10333,10336,10341,10343,10363,9757,9902,9908,9984,9990,10016,10305,10329,10335,10339,9873,9891,9889,9893,9987,10303,9896,9899,9986))",
            "cost_info": {
              "read_cost": "44.16",
              "eval_cost": "7.40",
              "prefix_cost": "51.56",
              "data_read_per_join": "1K"
            },
            "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": 3,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "18.50",
              "eval_cost": "0.37",
              "prefix_cost": "77.46",
              "data_read_per_join": "11K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}