Problem with select by attributes

I've got problem with python to use select by attributes to my layer called "World Cities". I type this script:

arcpy.SelectLayerByAttribute_management ("World Cities","NEW_SELECTION","CITY_NAME" = 'Abancay')

and I see :
Runtime error SyntaxError: keyword can't be an expression (<string>, line 1)

When I'm trying this tool in arcgis not by python everything is ok, but in script I see this error. Please help!