SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da1155eb36eddbea683ec2f8e3ec496d75573b9adbb047ea345bdb7f141d7d3f' 
  AND token = 'Q/MwC3xHN/2F8Mm6D+a56cbfLEUDWk1QGLI9mbdh3ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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