How to view only the form entries with successful payments?
All the submitted records will be displayed in the All Entries section and we do not support the option to exclude the payment failure entries.
However, you can create a report
and configure
Custom Filters
to display the entries in which the payment has been successful as shown.

If you wish to exclude the test submissions made via
Sandbox
mode, you can apply a filter as:
Payment Mode Is live.