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 (
    1, 228, 8, 9, 10, 71, 4, 1549, 5851, 1550, 
    1548, 5737, 5995, 5728, 5879, 5968, 
    5920, 1551, 5876, 5902, 5860, 1546, 
    5846, 5897, 5880, 5782, 5985, 5784, 
    1547, 5767, 5780, 5844, 5764, 5872, 
    5971, 5841, 5768, 5835, 5910, 5873, 
    5853, 5901, 8266, 5763, 5855, 5921, 
    5883, 5904, 8265, 5769, 5772, 8267, 
    5886, 5906, 5996, 5783, 5913, 5781, 
    5842, 5840, 5986, 8264, 5770, 5916, 
    5865, 5867, 5907, 5771, 5903, 5776, 
    5889, 5874, 5834, 5878, 5875, 5877, 
    5905, 5963, 5863, 5909
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00297

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "163.21"
    },
    "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": 179,
            "rows_produced_per_join": 179,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (1,228,8,9,10,71,4,1549,5851,1550,1548,5737,5995,5728,5879,5968,5920,1551,5876,5902,5860,1546,5846,5897,5880,5782,5985,5784,1547,5767,5780,5844,5764,5872,5971,5841,5768,5835,5910,5873,5853,5901,8266,5763,5855,5921,5883,5904,8265,5769,5772,8267,5886,5906,5996,5783,5913,5781,5842,5840,5986,8264,5770,5916,5865,5867,5907,5771,5903,5776,5889,5874,5834,5878,5875,5877,5905,5963,5863,5909))",
            "cost_info": {
              "read_cost": "82.66",
              "eval_cost": "17.90",
              "prefix_cost": "100.56",
              "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": "44.75",
              "eval_cost": "0.90",
              "prefix_cost": "163.21",
              "data_read_per_join": "28K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}