How to securely connect to MySQL database on another server?

I'm attempting to link my Discord bot with a MySQL database that is on another server. However, this example is apparently insecure:

const mysql = require('mysql');
const connection = mysql.createConnection({
  host     : 'hostname',
  port     : 'portnum',
  user     : 'db_user',
  password : 'db_user_password',
  database : 'db_name',
  charset  : 'utf8mb4'
});

How would I go about establishing a (more) secure connection?

from How to securely connect to MySQL database on another server?