The ISTQB Foundation Level exam from ASTQB is 60 minutes.

If English is not your native language, you are eligible for a 25% time extension, meaning you will be given 75 minutes.

Other ISTQB exams from ASTQB vary from 60 minutes to 180 minutes. All of those are also eligible for the 25% time extension.

To see the complete list of ISTQB certification exams and times, go to the ASTQB ISTQB exam FAQ.