I think they might not let you in to AY biz lounge with an European connection. If they do, it is way better than its Schengen counterpart. They have a bar with some cocktails and most likely champagne as well because the Plat wing lounge is closed. Food is decent but not great.
You can also try if they let you in to Plaza Premium on the non-schengen side. Free access with AX Plat/Cent. If you don't have free access, I think it's not worth it.
On the non-Schengen side there is also Aspire lounge, which is usually no better than the AY lounge. However, food in AY lounge has sucked for some time (especially if you eat meat), so if you have a Prio Pass, this may be an option worth checking out.