The phrase "snap of a finger" is correct and usable in written English. You can use it to describe something that happened very quickly or to emphasize the speed of something, for example: "She finished the race in the snap of a finger.".
You cannot do it at the snap of a finger".
The 55 sprint seems to go by in the snap of a finger.
Most of us can't transition physically in the snap of a finger.
"Those are difficult things to move at the snap of a finger".
For team and league, two years is a snap of the finger, a blink of an eye, a chance to work on footwork and take small steps forward.
I was happy with my run, and unfortunately, I lost by one-hundredth of a second, which is a snap of your finger," Vonn said.
His best paintings deliver their word-image unity with a little flash, like the snap of a hypnotist's fingers or the popping of a big, beautiful bubble.
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK