The APO RODAGON D is one such lens, just to give OP an idea of what to look for 🙂
Lenses I know to be optimized for 1:1:
Olympus 80mm f/4 Macro (A bellows lens, some models allow a bit of touch-up focusing. The Olympus variable extension tube gives you some good options.)
And, the APO Rodagon 75mm f/4 D for 1:1. There is also an APO Rodagon D 75mm f/4.5 2x which is optimized for 1:2 in normal orientation and 2:1 when reversed. (1:2 means the subject is larger than the image, and vice versa.)
Enlarging lenses are optimized for 1:4 or maybe 1:8, depending on the lens and intended format. Reversed they do a good job at 3:1, 4:1, and more.
Your typical macro lens is optimized for 1:2 or 1:3 but many are good out to infinity 1:lots.
So what's the practical difference of a 1:1 optimized lens for SLR scanning? Most any lens, racked out really far to 1:1, will give reasonable sharpness in the center, macro lenses and enlarging lenses will do quite well. The difference will be in the edges and corners.
So, suppose you are shooting an insect. Soft borders won't be a big concern. But, if you are copying a stamp, a slide, or SLR-scanning a negative, might be a greater concern.
A different case: An ordinary macro lens, on APS or full frame SLR, will do a great job SLR-scanning of medium format film. But, then again, you might want to come in to 1:1 and stitch.
Good shooting!