I’d like to point out that the cancel button could be removed. There is the x (close) in the top right corner so it makes it redundant.
Also, I’ve watched someone try to hit the shift button and hit the cancel by accident, repeatedly (3-4 times). At the time I thought it was silly, but I’ve also found myself hitting it accidentally when trying to access the other keys near to it.
Making the cancel a left/right arrow key might kill two birds with one stone.
The x would still focus as an close without saving changes or close with saved changes depending upon if the “apply” button was pressed.