SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f57de030d69eded65e27e5a12f706cfb89948c2a95e4a46a6770fedef74e6a51' 
  AND token = 'xff9LShBekpaW4kwBGSB9ki7ASvMO2GxMCCcpAURxCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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