SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd0ed7344a674e72eb25c15981dec064d45c1f5255da58bbea645114f17b6845' 
  AND token = 'U9GG4FlNsQlDbyEW0yFcOBqTn5uUGp46XweycnQ36BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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