At the site level, if you want to include/exclude the aspx pages from crawling and to appear in search results. Here are the way to do it.
Steps
1. Go to Site Settings.
2. Click on Search and Offline Availability.
- Do not index ASPX pages if this site contains fine-grained permissions
- Always index all ASPX pages on this site
- Never index any ASPX pages on this site
The screenshot about the settings are attached here.