To see what keyboard shortcut bindings are currently set, and to add more without using xbindkeys, you can dig through the following file and edit it:
/home/<user>/.config/openbox/lxde-rc.xml
I imagine you can figure it out just fine, but for a quick start, at least on PC hardware,
A- means “Alt+”
C- means “Ctrl+”
S- means “Shift+”
W- means the “Windows” key
so, for example, C-A-T is ctrl+alt+”t”, which runs a terminal window.