SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'dc242c5f2850f19e1c48572262fc3ea6ef67fc8b71a719c1a43e9e5990c167b2' 
  AND token = 'ZrKBScRklmyXrrs6b1s/32ah9DKKmE87odDzeLy7aIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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