Scroll Lock.

I'm unaware of a keyboard shortcut for doing that. I use a CS to move the time line or markers. 

AFAIK, the closest you can get to a keyboard shortcut is to use Ctrl+Scrollwheel for horizontal scrolling.
 
EDIT: Should have stated Ctrl+Mouse Wheel instead of Scrollwheel. 
 
Hope this helps,
-- Ron

Ca,
There are no shortcuts for scrolling. there are few for jumping 1 bar at a time, marker at a time, exc.
but none that will control scroll.
My advise is to set up a custom hotkey on your own using the preferences, keyboard short cuts.
 
the closest you will get is linking some keys to do REW/FF/Center on Nowtime.