Query
Enable MySQL Slow Query Log
Edit Configure File /etc/my.cnf & Add Following Lines
#Slow Query Log
#Log file
log-slow-queries = /var/log/slow-queries-log
#Logs queries longer than 2 sec
long_query_time = 2
#Logs queries not using indexes
log-queries-not-using-indexes TRUE
Change Owner Permissions
chown mysql.mysql
Re-Start MySQL Service
service mysql restart
(or)
service mysqld restart