SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a230af5131afe067e5f627d015393662c61ab12c2444ec93407c37e85aad211e' 
  AND token = 'hoaKRwh1LXzAQM2SAM5zKJNq6St1UhvngrI5ocbuCo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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