Thank you for the quick response. The thing is that I am almost sure something like that exists. I once saw a theater photographer using one of these and he said it was a Zeiss lens as far as I remember.
The Canon 50mm f/0.95 S-mount is for a rangefinder, and if used on an EF mount it wouldn't be able to get anywhere near infinity focus. People use them on Leica M8 and M9 cameras.