SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c50d2edf105272b5160db5372684446aa30ccc12adf200568cfc0559174c40f' 
  AND token = 'VqzYeRC4CF8tGZRbPnoWIB9ZnJiCBV63ySs05shkfCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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