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, 
  product_position_source.position AS position 
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') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 7240 
WHERE 
  cscart_products_categories.product_id IN (
    87148, 87149, 87150, 87151, 87152, 87153, 
    87286, 87154, 87155, 87156, 87157, 
    87158, 87159, 87287, 87142, 87143, 
    87144, 87145, 87146, 87147, 87285, 
    87172, 87173, 87174, 87175, 87176, 
    87177, 87160, 87161, 87162
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01986

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "108.30"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "link_type",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 120,
            "rows_produced_per_join": 120,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "12.30",
              "eval_cost": "12.00",
              "prefix_cost": "24.30",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (87148,87149,87150,87151,87152,87153,87286,87154,87155,87156,87157,87158,87159,87287,87142,87143,87144,87145,87146,87147,87285,87172,87173,87174,87175,87176,87177,87160,87161,87162))"
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "nuie_scalesta_net.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 120,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "30.00",
              "eval_cost": "12.00",
              "prefix_cost": "66.30",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "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": [
              "nuie_scalesta_net.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "30.00",
              "eval_cost": "0.60",
              "prefix_cost": "108.30",
              "data_read_per_join": "15K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`nuie_scalesta_net`.`cscart_categories`.`storefront_id` in (0,1)) and ((`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`))) and (`nuie_scalesta_net`.`cscart_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
87142 7208M,7241,7309,7346
87143 7208M,7241,7309,7346
87144 7208M,7241,7309,7346
87145 7208M,7241,7309,7346
87146 7208M,7241,7309,7346
87147 7208M,7241,7309,7346
87148 7208M,7241,7309,7346
87149 7208M,7241,7309,7346
87150 7208M,7241,7309,7346
87151 7208M,7241,7309,7346
87152 7208M,7241,7309,7346
87153 7208M,7241,7309,7346
87154 7208M,7241,7309,7346
87155 7208M,7241,7309,7346
87156 7208M,7241,7309,7346
87157 7208M,7241,7309,7346
87158 7208M,7241,7309,7346
87159 7208M,7241,7309,7346
87160 7208M,7241,7309,7346
87161 7208M,7241,7309,7346
87162 7208M,7241,7309,7346
87172 7208M,7241,7309,7346
87173 7208M,7241,7309,7346
87174 7208M,7241,7309,7346
87175 7208M,7241,7309,7346
87176 7208M,7241,7309,7346
87177 7208M,7241,7309,7346
87285 7208M,7241,7309,7346
87286 7208M,7241,7309,7346
87287 7208M,7241,7309,7346