The string (and its variations) is a known Google Dork —an advanced search query used to find unintentionally exposed Axis network cameras on the public internet. What this Query Does
This refers to the VAPIX API used by Axis cameras to handle commands and stream video. inurl axis cgi mjpg motion jpeg hot
As long as the ?action=stream CGI script exists for compatibility, the inurl:axis cgi mjpg search string will continue to yield results. The string (and its variations) is a known