SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '370efc067450d5cd92336698549fb769af4eb3409c8f06f44ebddb06fa1df84b' 
  AND token = 'lwOFiAv0WOg1Nb7brolvGAds/qXXcjTw/+hZ6WZjsP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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