Amazon Web Services - cronjob not running every minute

I have a cronjob defined on an AWS ec2 (so it uses crontab). I did crontab -e and added this line into it:

*/1 * * * * /usr/bin/php /path/to/file/file.php

I saved it with vim and it says crontab: installing new crontab. I also made the permissions on the file 755, using chmod, and I put the proper shebang (#!/usr/bin/php -q) at the top of file.php. The script should update a database every minute, but I am not seeing the database get updated at all. What did I do wrong?