“Time-limited” vs “time-restricted” vs “temporary”
Solution 1:
Time-limited, from time limit:
A limit of time within which something must be done.
Oxford
English doesn't explicitly distinguish between these, but domain usage does. Temporary is commonly used for password resets that force a new password. Time-restricted may refer to a time of day, such as restricted to business hours. The definition of time-limited naturally encompasses the 48 hour period from the example.
Solution 2:
Temporal, as in a temporal cache. This word has an existing similar usage in software engineering, so likely to appeal to readers.