SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cda393cfc7ec6ddccdb91677de963801816a04cf859239493b0e8a4bff90bcd' 
  AND token = '4uDlirITSp4l4jGcjvXr7Dw5vJ8aPWwHh0RwHz/+q9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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