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 (
    5485, 5479, 5420, 5518, 5441, 5434, 5590, 
    5417, 5541, 5406, 5407, 5493, 5526, 
    5484, 5412, 5583, 5680, 5416, 5482, 
    5544, 5589, 5600, 5487, 5418, 5421, 
    5499, 5521, 5532, 5597, 5455, 5512, 
    5560, 5562, 5588, 5669, 5525, 5679, 
    5533, 5974, 5579, 5584, 5481, 5489, 
    5428, 5524, 5591, 5511, 5419, 5495, 
    5423, 5424, 5480, 5486, 5657, 5546, 
    5543, 5440, 5547, 5548, 9547, 5438, 
    5443, 5476, 5542, 5592, 5585, 5649, 
    5447, 5529, 5439, 5659, 5602, 5496, 
    5656, 5475, 5433, 5498, 5603, 5432, 
    5514
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00351

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "180.81"
    },
    "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": 201,
            "rows_produced_per_join": 201,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (5485,5479,5420,5518,5441,5434,5590,5417,5541,5406,5407,5493,5526,5484,5412,5583,5680,5416,5482,5544,5589,5600,5487,5418,5421,5499,5521,5532,5597,5455,5512,5560,5562,5588,5669,5525,5679,5533,5974,5579,5584,5481,5489,5428,5524,5591,5511,5419,5495,5423,5424,5480,5486,5657,5546,5543,5440,5547,5548,9547,5438,5443,5476,5542,5592,5585,5649,5447,5529,5439,5659,5602,5496,5656,5475,5433,5498,5603,5432,5514))",
            "cost_info": {
              "read_cost": "90.36",
              "eval_cost": "20.10",
              "prefix_cost": "110.46",
              "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": "50.25",
              "eval_cost": "1.01",
              "prefix_cost": "180.81",
              "data_read_per_join": "31K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}