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, 2729, 2730, 2731, 
    2732, 2746, 2747, 2749, 2750, 2751, 
    2752, 2753, 2754, 2755, 2756, 2757, 
    2822, 2823, 2824, 2825, 2826, 2869, 
    2870, 2871, 2927, 2928, 2929, 3026, 
    3030, 3029, 3090, 3091, 3092, 3093, 
    3094, 3140, 3141
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00331

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "155.36"
    },
    "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": 172,
            "rows_produced_per_join": 172,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (908,134,1142,853,1146,1145,1144,1143,856,1540,1541,1542,1543,1544,1545,2258,2257,2256,2255,2260,2259,2251,2262,2261,2252,2265,2264,2263,2253,2267,2266,2254,2559,2560,3663,2729,2730,2731,2732,2746,2747,2749,2750,2751,2752,2753,2754,2755,2756,2757,2822,2823,2824,2825,2826,2869,2870,2871,2927,2928,2929,3026,3030,3029,3090,3091,3092,3093,3094,3140,3141))",
            "cost_info": {
              "read_cost": "77.96",
              "eval_cost": "17.20",
              "prefix_cost": "95.16",
              "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": 8,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "43.00",
              "eval_cost": "0.86",
              "prefix_cost": "155.36",
              "data_read_per_join": "26K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}