SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45b9b3f54bbd7e0246dd69835bf8d8cdff48be994da515fc973882c02351edce' 
  AND token = 'Aw59JAIcdVgsHVfu+7crAD7yzIN98TuUwDJDh2lulb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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