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 = 'ar' 
WHERE 
  cscart_product_feature_variants.variant_id IN (
    3985, 1607, 1560, 1913, 1559, 4913, 4696, 
    2077, 4694, 1558, 1707, 4699, 2862, 
    2696, 4705, 2315, 2895, 2758, 1609
  ) 
ORDER BY 
  cscart_product_feature_variants.position ASC, 
  cscart_product_feature_variant_descriptions.variant ASC

Query time 0.00136

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "19.96"
    },
    "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": 19,
            "rows_produced_per_join": 19,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_feature_variants`.`variant_id` in (3985,1607,1560,1913,1559,4913,4696,2077,4694,1558,1707,4699,2862,2696,4705,2315,2895,2758,1609))",
            "cost_info": {
              "read_cost": "11.41",
              "eval_cost": "1.90",
              "prefix_cost": "13.31",
              "data_read_per_join": "21K"
            },
            "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": [
              "softwarepirmam_hewadelivard_cscart_4.cscart_product_feature_variants.variant_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 19,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "4.75",
              "eval_cost": "1.90",
              "prefix_cost": "19.96",
              "data_read_per_join": "57K"
            },
            "used_columns": [
              "variant_id",
              "variant",
              "lang_code"
            ]
          }
        }
      ]
    }
  }
}