Set up your four page document the way you normally would. In a case like this, I'd probably turn off Facing Pages in the document setup dialog, but it doesn't really make a difference.
In the Pages panel flyout menu, turn off "Allow Document Pages to Shuffle." (This never makes sense to me, since the whole point is to let me shuffle them, but they mean "shuffle automatically" when you move a page from one spread to another.)
Drag a page thumbnail to the right edge of the first page, until you see a black "]" appear at that right edge. Let go. The page thumbnails will snap together, and in the document window you'll see the two pages side by side, like a regular spread.
Repeat for the remaining two panels to make a "four page spread" in the main document window.
One of InDesign's neater little tricks, imho.