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 = 7170 
WHERE 
  cscart_products_categories.product_id IN (
    83533, 83534, 89769, 85129, 86132, 86155, 
    86640, 86709, 82854, 82927, 83000, 
    83516, 83524, 86175, 86176, 86198, 
    86199, 84497, 84498, 84563, 84564, 
    82803, 82804, 82876, 82877, 82949, 
    82950, 83021, 85101, 89049, 89050, 
    90857, 90936, 91102, 91103, 91188, 
    91189, 91243, 91244, 85365, 89803, 
    89804, 89855, 89856, 89927, 89928, 
    91493, 91494, 85840, 85841, 84649, 
    84650, 87302, 87303, 89070, 83613, 
    85087, 85173, 85219, 85265, 82830, 
    82903, 82976, 89801, 89853, 89925, 
    91491, 85066, 85067, 85152, 85153, 
    85198, 85199, 85244, 85245, 89773, 
    89774, 84345, 84346, 86173, 86174, 
    86196, 86197, 85856, 85857, 85866, 
    85867, 86138, 86139, 86161, 86162, 
    86646, 86647, 86715, 86716, 82834
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00273

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "89.41"
    },
    "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": 157,
            "rows_produced_per_join": 157,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "16.02",
              "eval_cost": "15.70",
              "prefix_cost": "31.72",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (83533,83534,89769,85129,86132,86155,86640,86709,82854,82927,83000,83516,83524,86175,86176,86198,86199,84497,84498,84563,84564,82803,82804,82876,82877,82949,82950,83021,85101,89049,89050,90857,90936,91102,91103,91188,91189,91243,91244,85365,89803,89804,89855,89856,89927,89928,91493,91494,85840,85841,84649,84650,87302,87303,89070,83613,85087,85173,85219,85265,82830,82903,82976,89801,89853,89925,91491,85066,85067,85152,85153,85198,85199,85244,85245,89773,89774,84345,84346,86173,86174,86196,86197,85856,85857,85866,85867,86138,86139,86161,86162,86646,86647,86715,86716,82834))"
          }
        },
        {
          "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": 7,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "39.25",
              "eval_cost": "0.79",
              "prefix_cost": "86.67",
              "data_read_per_join": "20K"
            },
            "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": 7,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.96",
              "eval_cost": "0.79",
              "prefix_cost": "89.41",
              "data_read_per_join": "125"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}