var lockers = Array(number_locker).fill(Array(number_shelves).fill(0));

const conn = mysql.createConnection({
   .....................
});

var sql = 'SELECT `locker_id`, `shelve_id` FROM `shelves`';
conn.query(sql, function(err, result) {
    if (err) throw err;

    result.forEach(function(item, i, arr) {
        lockers[item.locker_id][item.shelve_id] = 1;
        console.log(item.locker_id, item.shelve_id);
    });
});

lockers[1][1] = 1;

var lockers = new Array(number_locker).fill(0).map(el => new Array(number_shelves).fill(0));