SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f35c57879a409adb89745034adec28ffd182a828872d066dd3082de6715e299' 
  AND token = 'm/2ICjwmHJB3WdmwNloN43fJpw99F9oIimcUQQg6Kis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}