Slow query log is not storing slow queries
There are two ways to collect general and slow logs:


File (this is the default)
Table (this needs to be specifically enabled)


Based on the info you provided, it looks like MySQL is using the default value for log_output which is "Log output goes to file(s) defined by general_log_file and slow_query_log_file". You can verify this by looking at these files (look in folder /usr/local/mysql/data/ and see what *.log files are there)

If you want the logs to go to database, on a MySQL client when logged in as a privileged user e.g. root:


SET GLOBAL log_output='TABLE';
SET GLOBAL general_log=ON;
SET GLOBAL slow_query_log=ON;
SET GLOBAL long_query_time=0;


The above will send global and slow logs to mysql.general_log and mysql.slow_log tables.

Note that I have set long_query_time to 0 seconds i.e. every query goes to slow_log(that is lot of output into the table). You can change this to another value that suits your use case.

Also, general_log produces a huge amounts of logs so you should only enable it for certain amount of time.