Sometimes it can also be found in Asian designs in fretwork borders or screens, but we most often associate the keys with neoclassical interiors and various revivals.
Check out this rad hand-painted key border by Jean Cocteau. I would love the chance to draw or graffiti something like this in an interior space with a big fat marker:
(Check out the rest of this French home that Cocteau designed in this article.)
I'm totally going to get these Euro shams from West Elm and use them as a summery headboard:
Go ahead and go Greek this year--get yourself a brand new key!