SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7711bd9fe057ffe20ea55ce733fbd44442c4ff1656823c78a07b234831a5b55e' 
  AND token = 'bWLFWS19Lr+07j65JhOVTCcRZZDv/cO0iOgAGra+brQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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