Fast and quick are the same thing. However, it is important to know that quick can also refer to a period of time, instead of just the speed of something, which fast normally refers to. That being said, they are usually interchangeable.
UM ... Contributors, the recommended answer for this question is entirely broken. Duo literally just translated: O teclado fica sujo rápido -> It will turn back on in 1 hour. I am I surprised, no, but it should be fixed!