The phrase "living a year in a minute" would be used to express the idea that something so big--and usually so stressful--happened in a short time that it is as if the one who experienced lived an entire lifetime in a moment. We might use it this way: When I opened my patio door and found a full-grown bear staring back at me, I lived a year in a minute. (Rather like being so frightened or nervous that I literally just aged a year or lost a year of my life.)
In Richard Connell's "The Most Dangerous Game," this is exactly how Sanger Rainsford feels every time General Zaroff nearly catches him, because he knows that this is a serious hunt for Zaroff. The line is used on the second day of the hunt, when Rainsford has made his Burmese tiger pit and has nothing to do but wait to see if it will work.
As he is kneeling behind a tree stump in the dark, Rainsford
knew his pursuer was coming; he heard the padding sound of feet on the soft earth, and the night breeze brought him the perfume of the general's cigarette. It seemed to Rainsford that the general was coming with unusual swiftness; he was not feeling his way along, foot by foot. Rainsford, crouching there, could not see the general, nor could he see the pit. He lived a year in a minute.
Rainsford's heart must have been thumping wildly and he was undoubtedly as frightened as he had ever been in his life. He is relieved when, a few minutes later, he hears something fall into the pit. It is not Zaroff, but it is one of his dogs, and Zaroff commends Rainsford for his cunning before leaving for the night.