Not all literary magazines publish flash fiction or micro memoirs. How can you tell if a journal will publish this genre?
First, do a quick Google search. There are a handful of online literary magazines devoted to flash fiction. Read some examples and check out author biographies - where else are they publishing their work? Investigate those publications.
Don't stop at Google, though! Read widely and pay attention to where you find flash fiction. Where are the authors that you admire publishing? If you discover a piece of flash fiction in an anthology, look at the acknowledgements section or the copyright page to see where the piece was first published. Investigate that publication further.
You can also conduct research to locate potential publication venues and determine if they will publish the flash fiction. The resources below will help you find literary magazines to investigate: