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 = 7157 
WHERE 
  cscart_products_categories.product_id IN (
    85571, 85573, 85574, 91877, 91878, 91879, 
    91880, 91881, 91882, 91883, 85555, 
    85594, 85564, 90025, 85575, 86889, 
    86895, 82359, 87888, 91844, 92185, 
    92382, 85561, 91856, 82370, 86893, 
    85553, 85559, 92172, 92358
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00177

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "63.86"
    },
    "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": 112,
            "rows_produced_per_join": 112,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "11.50",
              "eval_cost": "11.20",
              "prefix_cost": "22.70",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (85571,85573,85574,91877,91878,91879,91880,91881,91882,91883,85555,85594,85564,90025,85575,86889,86895,82359,87888,91844,92185,92382,85561,91856,82370,86893,85553,85559,92172,92358))"
          }
        },
        {
          "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": 5,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "28.00",
              "eval_cost": "0.56",
              "prefix_cost": "61.90",
              "data_read_per_join": "14K"
            },
            "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": 5,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.40",
              "eval_cost": "0.56",
              "prefix_cost": "63.86",
              "data_read_per_join": "89"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
82359 7148,7156,7157M 0
82370 7148,7156,7157M 0
85553 7341,7342,7343,7157M 0
85555 7341,7342,7343,7157M 0
85559 7341,7342,7343,7157M 0
85561 7341,7342,7343,7157M 0
85564 7341,7342,7343,7157M 0
85571 7341,7342,7343,7157M 0
85573 7341,7342,7343,7157M 0
85574 7341,7342,7343,7157M 0
85575 7341,7342,7343,7157M 0
85594 7341,7342,7343,7157M 0
86889 7341,7342,7343,7157M 0
86893 7341,7342,7343,7157M 0
86895 7148,7156,7157M 0
87888 7341,7342,7343,7157M 0
90025 7341,7342,7343,7157M 0
91844 7156,7157,7148M 0
91856 7156,7157,7148M 0
91877 7341,7342,7343,7157M 0
91878 7341,7342,7343,7157M 0
91879 7341,7342,7343,7157M 0
91880 7341,7342,7343,7157M 0
91881 7341,7342,7343,7157M 0
91882 7341,7342,7343,7157M 0
91883 7341,7342,7343,7157M 0
92172 7156,7157,7148M 0
92185 7341,7342,7343,7157M 0
92358 7156,7157,7148M 0
92382 7156,7157,7148M 0