@colibrisan,
You can hide the zoom / reset toolbar by changing CSS display property to block or none based on some conditions as shown in the code snippet below,
if(e.trigger === "reset" || (e.source == "buttons" && e.index == 3) || (e.source === "navigator" && e.minimum <= minimum && e.maximum >= maximum)) { //condition check for reset button on toolbar
document.getElementsByClassName("canvasjs-chart-toolbar")[2].style.display = "none";
}
else if((e.trigger ==="zoom" || e.trigger === "pan") || e.source === "buttons" || (e.source === "navigator" && e.minimum >= minimum && e.maximum <= maximum)) {
document.getElementsByClassName("canvasjs-chart-toolbar")[2].style.display = "block";
}
Kindly take a look at this updated JSFiddle for an example on the same.

—
Adithya Menon
Team CanvasJS