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 = 7340 
WHERE 
  cscart_products_categories.product_id IN (
    94453, 94454, 94455, 94456, 94458, 94459, 
    94460, 94461, 94462, 94751, 94752, 
    94753, 94754, 94755, 94756, 94757, 
    94758, 94762, 94764, 95565, 95567, 
    95568, 95570, 95572, 95573, 95576, 
    95577, 95582, 95583, 95584, 95585, 
    95586, 95639, 95654, 95934, 95937, 
    95941, 96206, 96207, 96208, 96601, 
    96604, 96605, 96607, 96609, 96611, 
    96614, 96615, 96620, 96621, 96622, 
    96623, 96624, 96678, 96694, 97083, 
    97219, 97220, 97221, 97222, 97223, 
    97224, 97225, 97226, 97227, 97567, 
    97570, 97573, 97576, 97577, 97578, 
    97579, 97580, 97582, 97583, 97584, 
    97585, 97586, 97875, 97876, 97877, 
    97878, 97879, 97880, 97881, 97882, 
    97886, 97888, 98001, 98176, 98177, 
    98178, 98179, 98180, 98181, 98182
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01565

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "141.90"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "14.93"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 208,
            "rows_produced_per_join": 8,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "20.72",
              "eval_cost": "0.83",
              "prefix_cost": "21.55",
              "data_read_per_join": "21K"
            },
            "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": "cscart_products_categories",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "link_type",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "nuie_scalesta_net.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 117,
            "rows_produced_per_join": 14,
            "filtered": "1.53",
            "cost_info": {
              "read_cost": "2.33",
              "eval_cost": "1.49",
              "prefix_cost": "121.75",
              "data_read_per_join": "238"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (94453,94454,94455,94456,94458,94459,94460,94461,94462,94751,94752,94753,94754,94755,94756,94757,94758,94762,94764,95565,95567,95568,95570,95572,95573,95576,95577,95582,95583,95584,95585,95586,95639,95654,95934,95937,95941,96206,96207,96208,96601,96604,96605,96607,96609,96611,96614,96615,96620,96621,96622,96623,96624,96678,96694,97083,97219,97220,97221,97222,97223,97224,97225,97226,97227,97567,97570,97573,97576,97577,97578,97579,97580,97582,97583,97584,97585,97586,97875,97876,97877,97878,97879,97880,97881,97882,97886,97888,98001,98176,98177,98178,98179,98180,98181,98182))"
          }
        },
        {
          "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": 14,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "3.73",
              "eval_cost": "1.49",
              "prefix_cost": "126.97",
              "data_read_per_join": "238"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}