By default resumption tokens are valid for 30 minutes, but you can change that according to your requirements.
Maintenance
When serving large amounts of records the OAI-PMH2 Data Provider splits the result set in batches issuing resumption tokens for flow control. Those are kept in the database, but expire after a certain time. It is therefore advisable to set up a cronjob to regularly prune expired tokens. The job should run daily and call the following CLI command.
# Make sure to use the right path for your environment
php /var/www/oai-pmh2/bin/cli oai:prune:tokens --quietThe --quiet
flag suppresses all output except error messages which should be redirected and handled properly.