SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c238123e986b57c317eab78717072d1523be53dfbf532f348de7c6bcb8bf673' 
  AND token = 'v8JGWTMsrB2ZngOxPVwmqzkE/h4goPCB8GbEpGMULkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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