SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd431de12706c953fcf3bb85e380f075404ad984342e2a3dad6e8bad6987d41e9' 
  AND token = '99gEciP1YQA7knkuh0i45QIkWqtCf/MxJqWRpKubfTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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