SELECT 
  pfv.feature_id, 
  pfv.product_id, 
  pfv.variant_id, 
  fv.position, 
  fvd.variant 
FROM 
  cscart_product_features_values AS pfv 
  INNER JOIN cscart_product_feature_variants AS fv ON pfv.feature_id = fv.feature_id 
  AND pfv.variant_id = fv.variant_id 
  INNER JOIN cscart_product_feature_variant_descriptions AS fvd ON pfv.variant_id = fvd.variant_id 
  AND fvd.lang_code = 'vi' 
WHERE 
  pfv.feature_id IN (
    23744, 21383, 22337, 19628, 23357, 24063, 
    21666, 22348, 21024, 21225, 19804, 
    21229, 20463, 24545, 22517, 19999, 
    20107, 20458, 21013
  ) 
  AND pfv.product_id IN (
    36733, 1897, 401, 6577, 6058, 46181, 
    1412, 6061, 382, 2502, 2136, 6063, 2132, 
    3875, 6062, 44939, 112, 6057, 5567, 
    5141, 3880, 2513
  ) 
  AND pfv.lang_code = 'vi'

Query time 0.01857

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "pfv",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "fl",
            "variant_id",
            "lang_code",
            "product_id",
            "fpl",
            "idx_product_feature_variant_id"
          ],
          "key": "PRIMARY",
          "key_length": "6",
          "used_key_parts": ["feature_id", "product_id"],
          "rows": 444,
          "filtered": 0.02047761,
          "attached_condition": "pfv.feature_id in (23744,21383,22337,19628,23357,24063,21666,22348,21024,21225,19804,21229,20463,24545,22517,19999,20107,20458,21013) and pfv.product_id in (36733,1897,401,6577,6058,46181,1412,6061,382,2502,2136,6063,2132,3875,6062,44939,112,6057,5567,5141,3880,2513) and pfv.lang_code = 'vi'",
          "using_index": true
        }
      },
      {
        "table": {
          "table_name": "fv",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "feature_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["variant_id"],
          "ref": ["dev_db.pfv.variant_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "fv.feature_id = pfv.feature_id"
        }
      },
      {
        "table": {
          "table_name": "fvd",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["variant_id", "lang_code"],
          "ref": ["dev_db.pfv.variant_id", "const"],
          "rows": 1,
          "filtered": 100,
          "index_condition": "fvd.lang_code = 'vi'"
        }
      }
    ]
  }
}