SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9095ea14534ebf62ccb20ce402a9067afb28da18b96a5fde30715d6c9d32be96' 
  AND token = '+lT1UMaygZBw7s5aAwRA2hswVCno66pGeJq0BVlx4UI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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