You can change the timezone in MySQL using php function CONVERT_TZ.
Following is the SQL command to change the timezone.
SELECT CONVERT_TZ( NOW(),'current-time-zone','changed-time-zone' );
If your current time zone is MST and you want to change the time zone to USA new york, you can fire the below command.
SELECT CONVERT_TZ( NOW(),'US/MST','America/New_York' );