SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47d608da25264fbd036afbf3ebd790182ae2d0dcba197aac3fbe208db7ab0caf' 
  AND token = 'BOSTJYBvmCcrPH/cpz7WSDh2ZBgRXRwGF60cb6QvS/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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