SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2fff1539aa6e85718d29d63e8a9007881fd293464bef583b65b8812f26c9742e' 
  AND token = 'YQxzUUwPXUSUMub4vhEwa5VZ1ZqeCjA6KFuoROV00hM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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