How long/deep is it? Do you have touch up paint?
It will never look 100%, but you can get really close. If you have more than foot of key mark, you can try to make it look better.
The reason I say one foot is becasue you can do half, and it if it come out crappy, you still have the other half of the unrepaired key mark to show insurance.
Anywho, if it is deep (primer or deeper) then you can try fill, wetsanding, fill, wetsand, etc. then polish. Time consuming; yes. Be careful on your scion, I hear the paint is thin.
It if is not deep, then you can just try a little wetsanding and polish.
Either way, let us know how it turns out. You can search a little too for info on fixing/past DIY's on it.