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 (
    25127, 24832, 20381, 20511, 23779, 23780, 
    25022, 25021, 23699, 23700, 20665, 
    20539, 23693, 23692, 20532, 20990, 
    22243, 22245, 20836, 23777, 24181, 
    24182
  ) 
  AND pfv.product_id IN (
    50216, 47597, 18608, 3713, 37096, 27357, 
    36399, 19386, 3662, 36339, 3666, 2553, 
    534, 25180, 3004, 37097, 40928
  ) 
  AND pfv.lang_code = 'vi'

Query time 0.03689

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": 400,
          "filtered": 0.910036385,
          "attached_condition": "pfv.feature_id in (25127,24832,20381,20511,23779,23780,25022,25021,23699,23700,20665,20539,23693,23692,20532,20990,22243,22245,20836,23777,24181,24182) and pfv.product_id in (50216,47597,18608,3713,37096,27357,36399,19386,3662,36339,3666,2553,534,25180,3004,37097,40928) 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'"
        }
      }
    ]
  }
}