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 (
    21629, 24836, 21219, 23141, 20574, 20184, 
    21220, 21425, 20573, 20196, 21418, 
    21424
  ) 
  AND pfv.product_id IN (
    23169, 47652, 2149, 29697, 19210, 4826, 
    2148, 1840, 19207, 4812, 1852, 1841
  ) 
  AND pfv.lang_code = 'vi'

Query time 0.03134

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": "idx_product_feature_variant_id",
          "key_length": "12",
          "used_key_parts": ["product_id", "feature_id", "lang_code"],
          "rows": 145,
          "filtered": 0.043292157,
          "attached_condition": "pfv.feature_id in (21629,24836,21219,23141,20574,20184,21220,21425,20573,20196,21418,21424) and pfv.product_id in (23169,47652,2149,29697,19210,4826,2148,1840,19207,4812,1852,1841) 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'"
        }
      }
    ]
  }
}

Result

feature_id product_id variant_id position variant
21425 1840 74965 0 Khăn lụa vuông - Xanh Dương
21424 1841 74960 0 Hoa văn xoắn màu xanh trên nền vàng
21418 1852 74937 0 Hồng hoa văn trắng
21220 2148 74227 0 Màu xám loang
21219 2149 74225 0 Màu xanh dương
20196 4812 70669 0 Size 36 (24cm)
20184 4826 70627 0 Size 36 (24cm)
20573 19207 71952 0 Sparkle Night
20574 19210 71956 0 Sparkle Night
21629 23169 75645 0 Mẫu 1
23141 29697 80234 1 Nhà thờ Đức Bà
24836 47652 86606 1 Mẫu vẽ hoa sen ngẫu nhiên