@ashans
Try repairing MySQL tables using phpMyAdmin. If not, here are the steps you can follow to do so.
1. Log in to phpMyAdmin or connect to it via your web hosting cPanel account.
2. Select the database with the crashed table.
3. Select “Repair table” from the “With selected:” drop down at the bottom of the list ( wp_options).
4. Sometimes it may be due to plugin overload conflicts. An incompatible plugin which you need to disable right away ( likely a cache / old version plugin if any ).
5. You are done!