SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1bc55f338b3e78f379dcfddba49aa2200ff0516633716064f6d4d28689c4d5cb' 
  AND token = 'Is8Rc22GBq8sOeRAC4quSsdoSNJoxHk7iSxiVbdgmLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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