SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee4d233cec2ab96fc66befeff25ee470df40e94017c3338283af90e7d99a3332' 
  AND token = 'rPSJSRnLmFBBNZoig+Ewt/OMBuKcPjrqJM3Jx3xLis8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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