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 (
    423, 424, 455, 433, 495, 453, 468, 467, 
    418, 420, 421, 422, 406, 407, 437, 494, 
    454, 442, 426, 429, 428, 410, 438, 440, 
    443, 463, 460, 450, 446, 447, 476, 457, 
    482, 483, 472, 441, 405, 403, 485, 492, 
    479, 480, 413, 401, 449, 474, 473, 448, 
    493, 409, 404, 456, 469, 431, 466, 402, 
    439, 484, 470, 490, 451, 491, 411, 486, 
    458, 459, 461, 462, 471, 425, 427, 416, 
    419, 464, 465, 432, 444, 445, 477, 478, 
    487, 488, 434, 435, 515, 481, 489, 415, 
    430, 414, 475, 452, 412, 417, 503, 514, 
    496, 497, 499, 512, 436, 498, 507, 513, 
    500, 511, 501, 502, 510, 506, 509, 508, 
    505, 504
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00116

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "45.62"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "5.02"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 98,
            "rows_produced_per_join": 3,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "22.49",
              "eval_cost": "0.78",
              "prefix_cost": "23.28",
              "data_read_per_join": "13K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`danishecarter_latest`.`cscart_categories`.`storefront_id` in (0,1)) and ((`danishecarter_latest`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`danishecarter_latest`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`danishecarter_latest`.`cscart_categories`.`usergroup_ids`)) and (`danishecarter_latest`.`cscart_categories`.`status` in ('A','H')))"
          }
        },
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "danishecarter_latest.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 3,
            "rows_produced_per_join": 5,
            "filtered": "42.67",
            "index_condition": "(`danishecarter_latest`.`cscart_products_categories`.`product_id` in (423,424,455,433,495,453,468,467,418,420,421,422,406,407,437,494,454,442,426,429,428,410,438,440,443,463,460,450,446,447,476,457,482,483,472,441,405,403,485,492,479,480,413,401,449,474,473,448,493,409,404,456,469,431,466,402,439,484,470,490,451,491,411,486,458,459,461,462,471,425,427,416,419,464,465,432,444,445,477,478,487,488,434,435,515,481,489,415,430,414,475,452,412,417,503,514,496,497,499,512,436,498,507,513,500,511,501,502,510,506,509,508,505,504))",
            "cost_info": {
              "read_cost": "14.97",
              "eval_cost": "1.00",
              "prefix_cost": "40.60",
              "data_read_per_join": "80"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}