SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ec37e09d96c6e770a10bc6957d25ca62eeab21e28f2c7db249295bd23640aee' 
  AND token = 'svk9cJ8nm2rfuGknrEJC145BXKxulEax0i4Z77kTpJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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