Syntax:
ENCRYPT(str[,salt])

Encrypts str using the Unix crypt() system call and returns a binary
string. The salt argument must be a string with at least two characters
or else the result is NULL. If no salt argument is given, a random
value is used.

*Note*:

The ENCRYPT() function is deprecated in MySQL 5.7, are removed in MySQL
8.0, and should no longer be used. For one-way hashing, consider using
SHA2() instead.

URL: https://dev.mysql.com/doc/refman/5.7/en/encryption-functions.html

