SELECT 
  pfv.variant_id, 
  pfv.position, 
  pfvd.variant 
FROM 
  cscart_product_feature_variants AS pfv 
  INNER JOIN cscart_product_feature_variant_descriptions AS pfvd ON pfv.variant_id = pfvd.variant_id 
  AND pfvd.lang_code = 'en' 
WHERE 
  pfv.variant_id IN (
    1716, 1718, 1461, 1717, 1715, 1464, 1720, 
    1722, 1721, 1719, 1724, 1470, 1469, 
    1468, 1466, 1723, 1728, 1727, 1456, 
    1726, 1725, 1730, 1729
  )

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "pfv",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["variant_id"],
      "rows": 23,
      "filtered": 100,
      "index_condition": "pfv.variant_id in (1716,1718,1461,1717,1715,1464,1720,1722,1721,1719,1724,1470,1469,1468,1466,1723,1728,1727,1456,1726,1725,1730,1729)"
    },
    "table": {
      "table_name": "pfvd",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["variant_id", "lang_code"],
      "ref": ["ymonline_livedata.pfv.variant_id", "const"],
      "rows": 1,
      "filtered": 100,
      "index_condition": "pfvd.lang_code = 'en'"
    }
  }
}