SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33f9d709a6552c8f47563ee898a9b8182f131c9f5fdc92c5a64129183a9f8b0d' 
  AND token = '865LmkX5n/IYU3pvVFR0D+SyU1i6/WQjtrujKJZY+GU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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