SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d89348cdac7561f8995ac9affd26a5159b7b2b54b96d043eca56c57f9c52c72' 
  AND token = 'YNwuoz3BVq8BmhoKTVNSnl1xIZxOUT96q8H5qEdE+Cs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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