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 = 7171 
WHERE 
  cscart_products_categories.product_id IN (
    91513, 86177, 86200, 86501, 86777, 86178, 
    86201, 86502, 86778, 82633, 82634, 
    83530, 83531, 85316, 85413, 85464, 
    85515, 86973, 87034, 89820, 89872, 
    89944, 91510, 82851, 82924, 82997, 
    83513, 83521, 85362, 83559, 83560, 
    83561, 83562, 89770, 89771, 84814, 
    84815, 84832, 84833, 84844, 84845, 
    91137, 91223, 91278, 83053, 83055, 
    83602, 83604, 90889, 90891, 90968, 
    90970, 82631, 83528, 83050, 83595, 
    90886, 90965, 84820, 84821, 91168, 
    89768, 83051, 83600, 90887, 90966, 
    89821, 89873, 89945, 91511, 87306, 
    87307, 87318, 87319, 87330, 87331, 
    87342, 87343, 85063, 85149, 85195, 
    85241, 83564, 83565, 85060, 85146, 
    85192, 85238, 86134, 86136, 86157, 
    86159, 86642, 86644, 86711, 86713
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00362

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "109.29"
    },
    "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": 192,
            "rows_produced_per_join": 192,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "19.53",
              "eval_cost": "19.20",
              "prefix_cost": "38.73",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (91513,86177,86200,86501,86777,86178,86201,86502,86778,82633,82634,83530,83531,85316,85413,85464,85515,86973,87034,89820,89872,89944,91510,82851,82924,82997,83513,83521,85362,83559,83560,83561,83562,89770,89771,84814,84815,84832,84833,84844,84845,91137,91223,91278,83053,83055,83602,83604,90889,90891,90968,90970,82631,83528,83050,83595,90886,90965,84820,84821,91168,89768,83051,83600,90887,90966,89821,89873,89945,91511,87306,87307,87318,87319,87330,87331,87342,87343,85063,85149,85195,85241,83564,83565,85060,85146,85192,85238,86134,86136,86157,86159,86642,86644,86711,86713))"
          }
        },
        {
          "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": 9,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "48.00",
              "eval_cost": "0.96",
              "prefix_cost": "105.93",
              "data_read_per_join": "25K"
            },
            "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": 9,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.40",
              "eval_cost": "0.96",
              "prefix_cost": "109.29",
              "data_read_per_join": "153"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}