for lack of better wording, explorer pass tickets are at the lowest level of the ranking for JAL services. No OLCI, no seat selection, no changes, no standby to earlier flight, no online upgrades, all other fares get priority for class J and F upgrades etc.
You only get saphire and emerald benefits if you are actually an elite member.
So, expect nothing but the explorer pass flight you booked, and you will be fine!