SELECT 
  cscart_product_feature_variants.variant_id, 
  cscart_product_feature_variants.position, 
  cscart_product_feature_variants.color, 
  cscart_product_feature_variant_descriptions.variant 
FROM 
  cscart_product_feature_variants 
  LEFT JOIN cscart_product_feature_variant_descriptions ON cscart_product_feature_variants.variant_id = cscart_product_feature_variant_descriptions.variant_id 
  AND cscart_product_feature_variant_descriptions.lang_code = 'de' 
WHERE 
  cscart_product_feature_variants.variant_id IN (
    21601, 21702, 18937, 18940, 18943, 22756, 
    22768, 22778, 22797, 23005, 23040, 
    18942, 21725, 18866, 18860, 18903, 
    19227, 19242, 23189, 22773, 22785, 
    23035, 18817, 23208, 22775, 21602, 
    18882, 22769, 22780, 21717, 21599, 
    22766, 18902, 22753, 22755, 22774, 
    23006, 23042
  ) 
ORDER BY 
  cscart_product_feature_variants.position ASC, 
  cscart_product_feature_variant_descriptions.variant ASC

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "136.81"
    },
    "ordering_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_product_feature_variants",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "variant_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 38,
            "rows_produced_per_join": 38,
            "filtered": "100.00",
            "index_condition": "(`danishecarter_latest`.`cscart_product_feature_variants`.`variant_id` in (21601,21702,18937,18940,18943,22756,22768,22778,22797,23005,23040,18942,21725,18866,18860,18903,19227,19242,23189,22773,22785,23035,18817,23208,22775,21602,18882,22769,22780,21717,21599,22766,18902,22753,22755,22774,23006,23042))",
            "cost_info": {
              "read_cost": "83.61",
              "eval_cost": "7.60",
              "prefix_cost": "91.21",
              "data_read_per_join": "100K"
            },
            "used_columns": [
              "variant_id",
              "color",
              "position"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_product_feature_variant_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "variant_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "danishecarter_latest.cscart_product_feature_variants.variant_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 38,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "38.00",
              "eval_cost": "7.60",
              "prefix_cost": "136.81",
              "data_read_per_join": "114K"
            },
            "used_columns": [
              "variant_id",
              "variant",
              "lang_code"
            ]
          }
        }
      ]
    }
  }
}