SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f6757d3cb5a124be00d39cc24bc167dfed38c96dc8016a7e94e731c3ac24c8d3' 
  AND token = 'ox0GwbNdT/jiQRVTw15WqROngwlnzR454UksmL0QGGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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