Steps to reproduce the issue

update from Joomla 3.8.12 to Joomla 3.8.13

Expected result

no Warning

Actual result

Warning
JInstaller: :Install: Error SQL Can't DROP 'series_2'; check that column/key exists
Files Update: SQL error file DB function failed with error number 1091
Can't DROP 'series_2'; check that column/key exists
SQL =
ALTER TABLE #__user_keys DROP INDEX series_2;

System information (as much as possible)

Joomla 3.8.13
PHP 7.1.22

Additional comments

How to fix this?