SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e652c48d46721977d23b8f1e64185806147433b9667635ab0cae684fb1748e5' 
  AND token = 'pIra6712ggteVrFBkLqKf3UAlZQgfEYPAUc0KrKO9WQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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