How about the shitty Sceptre specials from Walmart?

https://www.walmart.com/ip/Sceptre-50-Class-4K-UHD-LED-TV-U5...

> Let's you view your pictures as a slideshow or listen to your favorite music via the USB port. Just insert your flash drive into the USB port for the ultimate entertainment.

I'm pretty sure this is the one I have. But even if it's not, the fact they're advertising playing music via USB flash as the "ultimate entertainment" tells me this is not a smart tv.

Enjoy.

Edit: Oops, looks like it's out of stock. But you can probably find others if you just look for the shittiest 4k you can find. (You'll probably need to wait a bit as black friday probably annihilated the stock in this class of dumb tv.)