OK. If you are expecting to get a different value for parameter of timeToMinutes with each iteration, then you are mistaken. I think you need to get a better understand for how PHP and javascript work. PHP is only working at the time of page render. One the page is rendered, javascript would work within the browser. If you didn't put all the values you need from PHP into the javascript source, you have no way to get to them after the page is rendered, short of using AJAX techniques you pull the data in after initial page render.
I might suggest a technique like this:
// pre-populate array of values from PHP
// here PHP $query_results must be numerically indexed array
// there should be equal number of elements in this array and
// .menu-price-slider DOM elements
var timeToMinutesParams = <?php echo json_encode($query_results); ?>;
// iterate through DOM elements,
// using index of element to get matching value from timeToMinutesParams
$(".menu-price-slider").each(function(index) {
console.log(timeToMinutes(timeToMinutesParams[index]));
});