SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09620b3d4026cbad7fdc9e8959657c2e1270b8eb1141dff050681ed396fdf0fa' 
  AND token = '31rOuSOPfTP2K7gwYBy6KfXPDto0uVstjrleNPSyBaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}