Connolly Station have an automated locker system just on the left when you pass through the main platform exit/ticket checker, beside entrance to the toilets. That's a bit away from the RDS, but would be handy if you're passing through. They take small hand luggage or large suitcases. There's usualy a couple available. I've used them a few times and they're handy.
You'd have to check if you can access them 24/7 though, I'm not sure.