SELECT 
  v.variant_id, 
  v.product_id, 
  vd.variant, 
  vf.position, 
  vf.color 
FROM 
  cscart_product_features_values v 
  LEFT JOIN cscart_product_feature_variant_descriptions vd ON v.variant_id = vd.variant_id 
  AND vd.lang_code = 'en' 
  LEFT JOIN cscart_product_feature_variants vf ON v.variant_id = vf.variant_id 
WHERE 
  1 
  AND v.feature_id = 1451 
  AND v.product_id IN (
    '62315', '62316', '62317', '62318', 
    '62319', '62320', '62321', '62322', 
    '62323', '62324', '62325', '62326', 
    '62327', '62328', '62329', '62330', 
    '62331', '62332', '62333', '62334', 
    '62335', '62336', '62337', '62338'
  )

Query time 0.00129

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "22.09"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "v",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "fl",
            "product_id",
            "fpl",
            "idx_product_feature_variant_id"
          ],
          "key": "idx_product_feature_variant_id",
          "used_key_parts": [
            "product_id",
            "feature_id"
          ],
          "key_length": "6",
          "rows_examined_per_scan": 24,
          "rows_produced_per_join": 24,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "2.89",
            "eval_cost": "2.40",
            "prefix_cost": "5.29",
            "data_read_per_join": "18K"
          },
          "used_columns": [
            "feature_id",
            "product_id",
            "variant_id"
          ],
          "attached_condition": "((`cscartdb`.`v`.`feature_id` = 1451) and (`cscartdb`.`v`.`product_id` in ('62315','62316','62317','62318','62319','62320','62321','62322','62323','62324','62325','62326','62327','62328','62329','62330','62331','62332','62333','62334','62335','62336','62337','62338')))"
        }
      },
      {
        "table": {
          "table_name": "vd",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "variant_id",
            "lang_code"
          ],
          "key_length": "9",
          "ref": [
            "cscartdb.v.variant_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 24,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "6.00",
            "eval_cost": "2.40",
            "prefix_cost": "13.69",
            "data_read_per_join": "72K"
          },
          "used_columns": [
            "variant_id",
            "variant",
            "lang_code"
          ]
        }
      },
      {
        "table": {
          "table_name": "vf",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "variant_id"
          ],
          "key_length": "3",
          "ref": [
            "cscartdb.v.variant_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 24,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "6.00",
            "eval_cost": "2.40",
            "prefix_cost": "22.09",
            "data_read_per_join": "27K"
          },
          "used_columns": [
            "variant_id",
            "color",
            "position"
          ]
        }
      }
    ]
  }
}

Result

variant_id product_id variant position color
5842 62315 White 0 #000000
5842 62316 White 0 #000000
5842 62317 White 0 #000000
5842 62318 White 0 #000000
5842 62319 White 0 #000000
5842 62320 White 0 #000000
5842 62321 White 0 #000000
5842 62322 White 0 #000000
5842 62323 White 0 #000000
5842 62324 White 0 #000000
5842 62325 White 0 #000000
5842 62326 White 0 #000000
5843 62327 Black 1 #000000
5843 62328 Black 1 #000000
5843 62329 Black 1 #000000
5843 62330 Black 1 #000000
5843 62331 Black 1 #000000
5843 62332 Black 1 #000000
5843 62333 Black 1 #000000
5843 62334 Black 1 #000000
5843 62335 Black 1 #000000
5843 62336 Black 1 #000000
5843 62337 Black 1 #000000
5843 62338 Black 1 #000000