It's been about 5 hours for me and still no key.
On the REDitor website it said you'll receive the code in 72 Hours, but that it normally takes 6-24 hours. It also said that it mostly depends on the payment system, as some don't work on weekends.
Another thing is that it said that sometimes there is an error sending the email, so sometimes you have to send a manual one yourself saying you paid.
It's been less than 6 hours and it's also a weekend, so I can't expect it yet. Hopefully I get it by tomorrow morning.