The confirmation email and the email with the key have always been instantaneous for me, but I am not like other mortals it seems.
It is possible to retrieve keys manually. Log in to your store account and then go to Serial Keys, then scroll WAY DOWN to the bottom of the page to see if your recent purchase is there.
If it's not there, if your payment method didn't go through, or some other problem, then you may need to ask Jason about it , but wait a day first.