Yes — it is technically possible.

One historical solution is a lens turret: multiple lenses are mounted on a rotating mechanism so you can quickly switch which one is in front of the camera. This was common on older movie and film cameras.

It’s also possible to build a lens with discrete focal-length settings rather than a continuous zoom. Examples mentioned include Leica Tri-Elmar lenses with stepped focal lengths, and Canon’s 200-400mm lens with a switchable internal 1.4× extender.

For a 35mm/50mm-style lens, the most likely approach would be an internal optical group or converter that can be flipped into the light path. But in practice, that adds size, weight, complexity, cost, and often light loss or other compromises — many of the same tradeoffs as a zoom.

So the answer is yes, but it usually isn’t very practical. That’s why the real-world alternatives are typically:

• carry two primes,
• use a stepped or specialized lens design, or
• use a high-quality zoom if convenience matters more than the “one prime” experience.