Usually a rodent that is going to explode does so when struck and constricted. It can be from over soaking or just a rat that's not quite fresh or just a super strike. I have had it happen a few times but my snakes have always still eaten it. I wouldn't worry to much about it.

I would suggest submerging the prey in the hot water for about 20 minutes so the whole rodent warms thoroughly. I use the hottest water from my tap I can get. I thaw in warm water which for all the rats takes about 30-45min and then I drain the water and put fresh hot water for another 15-20mins to get them super warm.

You would be surprised by how fast they cool so you need to start warm. Its always better to present it a bit warmer than natural opposed to cooler.

Also a tip is to give the head a squeeze and make sure you dont feel any cold spots. Also do this in the stomach.