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 (
    4941, 4940, 4939, 4935, 5815, 5816, 5948, 
    6128, 6127, 6126, 6129, 6130, 6131, 
    6132, 6133, 6134, 6135, 5952, 6138, 
    6137, 6136, 6139, 6140, 6141, 6142, 
    6143, 6031, 6032, 6033, 6034, 6035, 
    6048, 6049, 6050, 6051, 6052, 6053, 
    6054, 6055, 6056, 6057, 6058, 6059, 
    5956, 6087, 6088, 6089, 6090, 6091, 
    6092, 6093, 6101, 6102, 6103, 6104, 
    6105, 6106, 6107, 6108, 6109, 6164, 
    6165, 6166, 6167, 6168, 6169, 6170, 
    6171, 6172, 6173, 6174, 6175, 6176, 
    6177, 5804, 6193, 6196, 6195, 6194, 
    6197, 6198, 6199, 6200, 6201, 6202, 
    10089
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00379

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "196.71"
    },
    "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": 219,
            "rows_produced_per_join": 219,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (4941,4940,4939,4935,5815,5816,5948,6128,6127,6126,6129,6130,6131,6132,6133,6134,6135,5952,6138,6137,6136,6139,6140,6141,6142,6143,6031,6032,6033,6034,6035,6048,6049,6050,6051,6052,6053,6054,6055,6056,6057,6058,6059,5956,6087,6088,6089,6090,6091,6092,6093,6101,6102,6103,6104,6105,6106,6107,6108,6109,6164,6165,6166,6167,6168,6169,6170,6171,6172,6173,6174,6175,6176,6177,5804,6193,6196,6195,6194,6197,6198,6199,6200,6201,6202,10089))",
            "cost_info": {
              "read_cost": "98.16",
              "eval_cost": "21.90",
              "prefix_cost": "120.06",
              "data_read_per_join": "3K"
            },
            "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": 10,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "54.75",
              "eval_cost": "1.10",
              "prefix_cost": "196.71",
              "data_read_per_join": "34K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}