SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '36109549aec8dc052df69e787e5e48d50bba85482493a2d370ebd8f53aabe441' 
  AND token = 'pS5Hh1OJ9F7sNxAXsMetJ4k2iv9Lu6c8LhMTC3AUFYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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