SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bec5de5111ba326c965ef9f7f51afa9adb53d8672c3339618dbdfd6e8af52dcb' 
  AND token = 'XKWEX3yCP/76li2XIj0qMYUxHPsxxjSuCZeUECCmwnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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