How to organize constant data synchronization with a third-party service?

Question

Yii

Good afternoon. There is a personal account for subscribers of one municipal enterprise. 1-3 personal accounts are attached to each subscriber account. These personal accounts are stored in the site's local database, but they need to be synchronized every 5-10 minutes with a third-party service. It makes no sense to update everything in a row, because. you need to update only those personal accounts whose subscribers are now online. What is the best way to organize this?
For me, it's best to store the online flag with the subscriber and run a cron task that will update the personal accounts of subscribers who are online. Does anyone have better options?