Contacted Canon with a similar issue for my Canon MX870 and they suggested the following (which worked for me):
Canon Imageformula Dr-2010c Mac Mojave Software Download Sites Pdf
Software Software Software. Download software for your Canon product. Manuals Manuals. Canon imageFORMULA DR-C240. Select your support content. View All Downloads View All Downloads Consumer Support. Canon imageFORMULA DR-C225 Specifications Request information. ISIS /TWAIN Driver.
Since there is no updated driver and software for your MX870, you can try downloading and installing the following Canon driver supplied by Apple. Since this is a third-party driver, Canon has not tested this and there's no assurance that it will work on your end.
Printer and scanner drivers for Mac (OS X Lion or later)
Once installed, you can then use Image Capture to perform scanning.
1. Turn on or wake up your printer, but dont press any other buttons on it.
2. On your Mac, click on the Finder icon on your Dock.
3. Click on the Go menu, and then select Applications.
4. Locate and double click on Image Capture to open it.
5. On the left-hand side, youll see two sections named Devices and Shared. Multifunction printers and scanners connected by USB cable will appear in the Devices section and networked or wireless devices will appear in the Shared section. (If your device isnt listed in either section, then it is not detected or its likely not compatible with Image Capture.)
Canon Dr 2010c Scanner Download
6. Click on your printer in either the Devices or Shared section to select it.
7. You might need to wait while your machine warms up.
8. Look at the picture below to see if your Image Capture looks similar. If not, click the Show Details button to expand the window so it looks like the image below. Click Scan.