Please. Absolutely not.
Predators have evolved over millions of years to be as efficient killers as possible.
Constrictors are some of the most efficient. They kill just as fast, or even quicker, than a CO2 chamber.
Constricting may even be more humane than a CO2 chamber because the constriction does stimulate endorphins, which do numb the pain receptors and reduce stress.
A ball python is specifically designed to kill rodents.
There is a reason why predators are nature's killers.
Natural selection favors those who can survive the best. Predators that kill efficiently are less likely to get inured, loose their prey, and survive.
A mouse eating a snake that is still aware and alive *IS* torture. I can bet that this snake did feel the mouse chew through it's tissue, bones, and organs before it eventually died a slow agonizing death. A domesticated mouse is not designed to kill snakes. They don't know how to kill efficiently and lack the instinct to kill efficiently. Even during a fight among the same species, rodents still do not kill efficiently.
Based on seeing a number of snake injuries from feeders left too long in the enclosure, the rodents certainly do eat the snake before it is dead. This snake most definitely did not die right away, which in my opinion is torture.