It's a category, "Geen Smart TV", under TV's. There are several for sale up to 55".
https://www.bol.com/nl/nl/l/42-inch-tv-s-zonder-smart-functi...
This Sony might be an option: https://www.bol.com/nl/nl/p/sony-bravia-professional-fw-55bz...
This Sony is an Android TV...
Ah right, I was looking on Google. Good to know there's a way to find dumb TVs!