How long will glutinous rice flour keep unopened?
As per this website: it should last 6-8 months past printed expiration date. 

However, this website says that when stored in a tightly covered container in a cool dry place, white rice flour may last indefinitely. You can also have a look at this answer which talks about bugs and rancidity.

I have previously kept rice flour in a plastic container inside the fridge and it's lasted me quite long, way past it's expiration date.