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 (
    1600, 1601, 1609, 1610, 2314, 2312, 2310, 
    2333, 2430, 2431, 2559, 2560, 3663, 
    2698, 2702, 2703, 2805, 2808, 2822, 
    2823, 2824, 2825, 2826, 2922, 2923, 
    2924, 2925, 2927, 2928, 2929, 3090, 
    3091, 3092, 3093, 3094, 3096, 3097, 
    3098, 3114, 3115, 3131, 3132, 3133, 
    3136, 3137, 3138, 3140, 3141, 3142, 
    3150, 3151, 3155, 3156, 2737, 3255, 
    3604, 3603, 3605, 3606
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00385

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "147.56"
    },
    "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": 166,
            "rows_produced_per_join": 166,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (1600,1601,1609,1610,2314,2312,2310,2333,2430,2431,2559,2560,3663,2698,2702,2703,2805,2808,2822,2823,2824,2825,2826,2922,2923,2924,2925,2927,2928,2929,3090,3091,3092,3093,3094,3096,3097,3098,3114,3115,3131,3132,3133,3136,3137,3138,3140,3141,3142,3150,3151,3155,3156,2737,3255,3604,3603,3605,3606))",
            "cost_info": {
              "read_cost": "72.86",
              "eval_cost": "16.60",
              "prefix_cost": "89.46",
              "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": "41.50",
              "eval_cost": "0.83",
              "prefix_cost": "147.56",
              "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')))"
          }
        }
      ]
    }
  }
}