SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfeccdacba4baedd7179bd681660fb29612db1914b608be32549877312dfc624' 
  AND token = 'qDvBy08nIcPgkKsRoK7PZ8X53SUeuIcaZGSy/4g4dXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}