In 2019, it takes approximately 24 hours to fly from Texas to China (depending on where in China you're going), which means the stratosphere plane is three times as fast as a modern commercial jet.
Being "Pathan" means that Kee-Shan is one of the Pashtun people who settled in the Punjab region of Pakistan. Kee-Shan seems an unlikely Pakistani name, but I love how he looks tailor made to be played by John Rhys-Davies in a Sky Wizard movie.
369.7 mph, a record set in August 1939. But that would be on a straight line -- Sky Wizard's supercharger can go 175 MPH on country roads with bends and corners, something I wouldn't want to try in even a modern day car.
Whether or not SW can make it to save the kids in time seems like a math puzzle worthy of Jim McClain's Solution Squad. He has six minutes left to get there. His supercharger can go 175 MPH, which is 2.9 Miles Per Minute and some change. It's 10 miles to Lone Pine, so it should only take him approximately 3.4 minutes to get there. This is close to SW's dialogue in panel 4; perhaps he just rounds up to four minutes.
The trick then is to find the fiends once he reaches Lone Pine. Clearly they aren't standing in the middle of the main road through town, for he has to spend two minutes searching the woods outside of town (I'm assuming Lone Pine is a town and not an actual lone pine tree!), which is less than a full exploration turn in Hideouts & Hoodlums game mechanics.
This brings me to two questions that I can't fully answer. One, why does Hawk set such a difficult deadline for SW to save the children by? Two, how does SW find them in the woods so quickly? I actually have a guess at the second answer -- the Editor may have allowed SW to spot their car from the road, which told him that they were nearby.
(Scans courtesy of Comic Book Plus.)