It looks like your MySql session has the safe-updates option set. This means that you can't update or delete records without specifying a key (ex. primary key) in the where clause. 


You can run the below query to disable safe mode,


SET SQL_SAFE_UPDATES = 0;

After this query try to run update password query in same table. 
Once operation completed, make sure you set it to default by running below command,
SET SQL_SAFE_UPDATES = 1;