How long does Gmail account recovery take to come back?

If you could verify with a code to your phone or recovery email it's basically instant. When it says it needs time to check that it's really you, there's no fixed answer, it can be anywhere from a few hours to a few days. Keep an eye on the contact email you gave it, spam folder included. And try to do any further attempts from the device and location you normally use Gmail on, that helps more than repeating it from somewhere new.