SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aa21bff0d37503ac21295a751206fd278ea2050adfcc8cad013f62723213870' 
  AND token = 'GfGbuNJQ39EbrF7aYurvECMJ35nyV6whQTCb7sqOujs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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