SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '774c57a8999c2c7630938518657c9885454463052c980f6541d2fd825c2265bc' 
  AND token = 'b6ipScKIYBkDRGRUqRKohv8i84eHDx2oX0+vBGa8lHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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