How to store cooked Quinoa for few hours at work?
You should always try to first bring hot quinoa to room temperature and follow the rest which you already mentioned. That works great, else if you try to pack it when it like burning hot, then the steam kind of stays in the packed room which later creates moisture and later spoils the food even though you keep it in the refrigerator. 

Best worked for me is by cooking quinoa in the night. Now I have lot of time to bring it to room temperature followed by pack it, store it and use it.