You hit about 120mph (terminal velocity for average human body in spread-eagle posture in the lower atmosphere) in the first seven seconds after the fall begins. Time to surface level from 5 miles altitude is a little over two and a half minutes.
However, unless one of the passengers had an oxygen bottle with them when the KAL jet was blown apart, oxygen deprivation (which occurs at altitudes greater than 10,000 - 15,000ft or so depending on the individual, call it three miles up) would have caused loss of consciousness and/or death long before their bodies hit the ground.
“Just prior to being attacked, the 747 had been cruising at an altitude around 35,000 feet. When the missile exploded, KAL 007’s tail was pushed downward which at the same time lifted its nose causing a brief altitude gain before it began to descend from 18:26 until recording ceased at 18:27:46. Capt. Chun was able to turn off the autopilot (18:26:46) and it is unknown whether he was able to regain any measure of control[8] as the aircraft spiraled toward the ocean around 5 miles (8 km) below after the cockpit voice recorder and flight data recorder stopped functioning. The final moments of the crash remain a matter of conjecture; some evidence suggests that the pilot may have attempted a controlled and ultimately unsuccessful ‘ditching’ into the ocean, or the aircraft may have crashed out of the pilot’s control.”
One does not immediately lose consciousness at that altitude. We don’t know what happened on board, but if they were conscious for the entire descent it’s a long time to stare death in the eye.