Yes! You can! Lynx can display the document as rendered text (translating the HTML code) or "as is" (without translating the HTML code). When viewing a document, press the SOURCE key (usually mapped to the "\" key) to display the source. You can now use the WHEREIS key (usually mapped to the "/" key) to search for text as usual.
Would you like to view the key bindings for the version of Lynx you are currently using? This won't work if you are not using Lynx, by the way.