How to get key and value from query in express node js

I'm building a rest API in node js and want to retrieve data from a query. Now I use this way

app.get('/delete/:key?/:value?', (req, res) => {
    let sql = `DELETE FROM data WHERE ${req.query.key}=${req.query.id}`;
    db.query(sql, (err, result) => {
        res.send(result);
    });
});

I want to do something like this

SELECT * FROM data WHERE {key}={value};

The key is taken from the "key" data sent by postman. Example link based on the code above

https://MY_LINK/post?key=1234&value=test

But I want to do something like

https://MY_LINK/post?1234=test

How to get key from postman (in this case is '1234') ??