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 (
    22370, 21922, 22369, 21215, 20287, 21748, 
    20277, 22566, 23735, 23926, 20276, 
    23734, 24717, 22563, 23739, 20284, 
    23491, 22570, 23737, 24438, 21424
  ) 
  AND pfv.product_id IN (
    350, 1044, 351, 2155, 4373, 23481, 4383, 
    2248, 36303, 38151, 4384, 36302, 49186, 
    2247, 36308, 4376, 33809, 2251, 36305, 
    43651, 1841
  ) 
  AND pfv.lang_code = 'vi'

Query time 0.02618

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": 473,
          "filtered": 0.03907498,
          "attached_condition": "pfv.feature_id in (22370,21922,22369,21215,20287,21748,20277,22566,23735,23926,20276,23734,24717,22563,23739,20284,23491,22570,23737,24438,21424) and pfv.product_id in (350,1044,351,2155,4373,23481,4383,2248,36303,38151,4384,36302,49186,2247,36308,4376,33809,2251,36305,43651,1841) 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'"
        }
      }
    ]
  }
}