The default option when exporting from InDesign is to export all of the pages/spreads in the document.
However, if you know where to look, exporting a single page is just as easy.
Here's how to do it:
- Select File > Export from the top menu
- Select desired export format from the drop-down menu, then click Save
- From the popup window’s left-hand menu, select General
- Under General, look for the Pages options box and check Range
- Enter range of pages to export (i.e. - to export only the third page, choose "3-3")
- Click the Export button