SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4398003709ef1d0458f53c36d3b863893f78e34dfaf4ea867b66e5177008f032' 
  AND token = 'dir9YOmCckI4hW/xSXehh/Iz8lGRYZLJZIM12z8+1TU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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