Possible Clues:

• Term with a check mark on an airport sign
• Fast-track program at the airport, briefly
• Airport express lane, briefly
• Skip-the-line status
• Letters with a green check mark at the airport
• Lead-in to a check mark, on a boarding pass
• Lax LAX option?
• Fast line at the airport, informally
• Lead-in to a check mark, at an airport