SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4e7de5c55d3f5ef17d85d9b9dacf311190a1823a9fd1cb45473e3115362d501c' 
  AND token = 'BO0KkhbmjT7IOjvV9XaJSRMHcUY2Yz7qzBoA7KvMWqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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