from Andreas' book "Mastering Bitcoin":
Locktime, or more technically nLockTime, is the part of a transaction which indicates the earliest time or earliest block when that transaction may be added to the block chain.
We are currently at ~500283, so behind the value in the tx (500114). So the tx is good to be processed by a miner.
I see 200 Bytes per Satoshi, also a "good" value, but based on "
https://bitcoinfees.earn.com" I guess it will take even longer then the displayed 3-120 blocks...