What? How would it be quicker to use a shortcut than just clicking? Your hand is already on the mouse.
Are there keyboard shortcuts for pawn promotion to choose queen,knight..?

Are you kidding? Alt-F4 is the shortcut for promotion to queen(apple+Q for Macs), whereas promotion for knights is Ctrl+Alt+Del, Geez.

Yes, there are keyboard shortcuts, which u have to type in the chat box. The shortcuts are:
"fu" for queen promotion
"gg" for rook promotion
"ha" for knight promotion
And something else for bishoppromotion that I don't remember, but you won't need to use it anyway. So next time when u want to promote ur pawn to a queen, just type "fu" in the chat box and it'll work!
if not should be. it can be very useful at last seconds.