Issues when pulling data from a mysql database in php

Question

I am reciving this error then I am trying to pull data from my database

Notice: Undefined offset: 0 in E:\xampp\htdocs\includes\connect.php on line 31

Notice: Undefined offset: 1 in E:\xampp\htdocs\includes\connect.php on line 31

<?php

$db_name = 'REDACTED';
$db_pass = 'REDACTED';
$db_user = 'REDACTED';
$db_host = 'REDACTED';

$mysqli = new mysqli($db_host,$db_user,$db_pass,$db_name);

if ($mysqli -> connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
    exit();
}

$sql = "SELECT 'key', 'name', 'id', 'dept', 'time', 'lastclockin' from dutylogs";

$result = $mysqli -> query($sql);

// Gets assosiative array
$row = $result -> fetch_array(MYSQLI_ASSOC);
printf("%s (%s)\n", $row[0], $row[1]);

$result -> free_result();

$mysqli-> close();