SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43e5a21372a58f6b1a77373d55b5cb9a512f6f2f6a92f7e27565f977856c9e8f' 
  AND token = 'VzlUhbo5jIHF1UXhRQOVZQAzqjUanxC/Ulwr4ITL2rU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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