Look at the sudoers manual on your system, and search for the password_timeout setting (the timeout for the password prompt) and timestamp_timeout settingssetting (how long until you will be asked for a password after having used sudo successfully). The manual on your system will mention the default timeouts that your system uses.
The default on Ubuntu is documented as 15 minutes for timestamp_timeout and 0 (no timeout) for password_timeout, but your system probably has another password_timeout. On FreeBSD and Alpine Linux, it's by default 5 minutes for both, for example, according to the sudoers manual on those systems.