SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f94f781aea3c7025b43afa07a9edd811f042eb5c66ae095265a3ebef58b3a556' 
  AND token = '3qxrwRjfgW/CO6ySDsNWhFHyfETzWt0vH5T1Jf9UtMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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