SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e15ebb1463aefba13d99150416b49b49dd3e4195cc424e933ca7c4aeaf06328' 
  AND token = 'h7lJ6uRFKb9VKTaMT+bIoCviray3JPYV0M9hRGvhEJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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