Is there a keyboard shortcut in OS X Mavericks for quick reply when an iMessage notification appears? I found it not that efficient to move the mouse pointer over the notification and click on the reply button every time.

So I was wondering if there is a hotkey for quick reply instead of using the mouse or the trackpad.
You could assign a keyboard shortcut to a script like this:

tell application "System Events" to click window 1 of process "Notification Center"