Peform a find to find only those subscription records that are not expired.
In find mode, enter < "Todays Date" into the expiration date, replacing "Todays Date" with the current date and perform the find.
I'm assuming your master table holds subscriber records and relates to the subscriptions table by a SubscriberID field.
Use Subsummary parts to show fields from the master table, specify your Subscription table's SubscriberID field as it's "sort by" field.
Sort your records by the same SubscriberID field and you are done. The report will be visible in browse mode if you are using FMP 10. With older versions, preview or print the report to see what it looks like.