It depends on the meal size, the type of boa, and the type of handling.
In general a BCI that has no history or regurge will be OK after 48 hours, but if it's a larger snake that is eating rabbits you may want to go 3 days. I would say a minimum would be 48 hours and you can adjust for meal size.
Now depending on what you mean by handling and duration things could change again.
When I get my snakes out, I usually hold them for a short time, and then build some type of climbing station made of chairs or bar stools and let them decide how active they want to be. Sometimes, they'll just perch and that's fine, and other times they'll cruise and explore.
The royal isn't a climber and she'll sit in a lap and soak up body heat.
If you have any issues with feeding or temperament after handling, you should look into limiting handling time and extend digestion.
Getting to know your snake will help.
Boa constrictors usually eat, drink, digest and defecate in a very predictable manner. Once you know what that is for your snake you can make adjustments if you think something isn't right.