mysql> status;
--------------
mysql  Ver 14.14 Distrib 5.7.25, for Linux (x86_64) using  EditLine wrapper

Connection id:          4
Current database:
Current user:           root@localhost
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server version:         5.7.25-0ubuntu0.16.04.2 (Ubuntu)
Protocol version:       10
Connection:             Localhost via UNIX socket
Server characterset:    latin1
Db     characterset:    latin1
Client characterset:    utf8
Conn.  characterset:    utf8
UNIX socket:            /var/run/mysqld/mysqld.sock
Uptime:                 25 min 2 sec

Threads: 1  Questions: 11  Slow queries: 0  Opens: 107  Flush tables: 1  Open tables: 26  Queries per second avg: 0.007
--------------

mysql> SELECT BENCHMARK(1000000,ENCODE('hello',RAND()));
+-------------------------------------------+
| BENCHMARK(1000000,ENCODE('hello',RAND())) |
+-------------------------------------------+
|                                         0 |
+-------------------------------------------+
1 row in set, 65535 warnings (14.95 sec)

mysql> SELECT BENCHMARK(1000000,AES_ENCRYPT('hello',RAND()));
+------------------------------------------------+
| BENCHMARK(1000000,AES_ENCRYPT('hello',RAND())) |
+------------------------------------------------+
|                                              0 |
+------------------------------------------------+
1 row in set (2.78 sec)