SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9baf5393b837424694e127d68d6258733609c4123835150817d43ac75327ffda' 
  AND token = '4ZMT3C4UGqI/BKRvMXIUTcrbF5w50dzIqzL6rdYfYnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}