Turn off Anti-aliasing with Quick Selection Tool / Object Selection Tool

Selection to QuickMask mode (q), threshold 128, exit QuickMask mode (q).

Easily recorded into an action for quick access via an F-key shortcut.

A script version would offer a custom keyboard shortcut for easier access.

128 is the middle value, adjust as necessary.

EDIT:

Here it is as a script –

#target photoshop

var selectionBounds = null;

try {
    selectionBounds = activeDocument.selection.bounds
} catch (e) {}
if (selectionBounds) {
    activeDocument.quickMaskMode = true;
    var idthresholdClassEvent = stringIDToTypeID("thresholdClassEvent");
    var desc188 = new ActionDescriptor();
    var idlevel = stringIDToTypeID("level");
    desc188.putInteger(idlevel, 128); // Adjust value as needed from 1-255
    executeAction(stringIDToTypeID("thresholdClassEvent"), desc188, DialogModes.NO);
    activeDocument.quickMaskMode = false;
} else {
    alert("A selection must be active!");
}

If you make a selection with either the Quick Selection Tool or the Object Selection Tool, you can select Hard Edge in the Options bar although it is still anti-aliased. 

For selections made by either of those tools, you could click on the Select and Mask button and in the Properties in the Select and Mask Workspace, set Contrast to 100%.

If you set that selection to Output to a Layer Mask, then you may see that you still have gray pixels. In that case, you can select the Layer Mask thumbnail in the Layers panel and go to Image > Adjustments > Threshold... to convert the pixels in the Layer Mask to either black or white.