When the Shadow-war Boosters expired the ones in the Redeeming Queue also did, even though they never had an expiry date like the daily ones, so I was under the impression they would last forever.
But ok, sitting on a pile of now useless Boosters is less of a problem than that I currently cannot remove them, I certainly cannot activate them and I cannot delete them either.
I am talking about over 70 of them (I am a hoarder, I know) and this is pretty annoying.
There is a trash can icon in the lower left corner of the redeeming queue window which allows deleting selected items from the redeeming queue.
And by the way, the expiry date of the boosters is mentioned in the info-window of the booster.