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 = 7254 
WHERE 
  cscart_products_categories.product_id IN (
    83883, 91764, 91580, 91581, 91582, 91583, 
    91584, 91585, 91586, 91587, 91588, 
    91589, 83877, 83880, 83889, 83890, 
    83893, 83895, 83884, 83886, 91627, 
    83891, 83892, 83896, 91700, 91701, 
    91702, 91703, 91704, 91705, 91706, 
    91707, 91571, 91572, 91573, 91574, 
    91575, 91576, 91577, 91578, 91579, 
    91610, 91611, 91612, 91613, 91614, 
    91615, 91616, 91617, 91618, 83879, 
    83881, 83887, 91787, 91796, 91797, 
    91798, 91799, 91800, 91801, 91802, 
    91803, 87870, 83894, 91622, 91698, 
    83885, 83888, 91626, 87867, 87868, 
    87869, 91620, 91540, 91541, 91542, 
    91543, 91544, 91545, 91546, 91547, 
    91548, 91549, 91624, 91804, 91805, 
    91806, 91807, 91808, 91809, 91810, 
    91811, 91621, 91601, 91602, 91603
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00296

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "55.34"
    },
    "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": 97,
            "rows_produced_per_join": 97,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "10.00",
              "eval_cost": "9.70",
              "prefix_cost": "19.70",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (83883,91764,91580,91581,91582,91583,91584,91585,91586,91587,91588,91589,83877,83880,83889,83890,83893,83895,83884,83886,91627,83891,83892,83896,91700,91701,91702,91703,91704,91705,91706,91707,91571,91572,91573,91574,91575,91576,91577,91578,91579,91610,91611,91612,91613,91614,91615,91616,91617,91618,83879,83881,83887,91787,91796,91797,91798,91799,91800,91801,91802,91803,87870,83894,91622,91698,83885,83888,91626,87867,87868,87869,91620,91540,91541,91542,91543,91544,91545,91546,91547,91548,91549,91624,91804,91805,91806,91807,91808,91809,91810,91811,91621,91601,91602,91603))"
          }
        },
        {
          "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": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "24.25",
              "eval_cost": "0.49",
              "prefix_cost": "53.65",
              "data_read_per_join": "12K"
            },
            "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')))"
          }
        },
        {
          "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": 4,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.21",
              "eval_cost": "0.49",
              "prefix_cost": "55.34",
              "data_read_per_join": "77"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}