SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9ea9a3944178e4dc6d20d3eb9fa52196d336dae4fe6d210508da659befa731af' 
  AND token = 'P7UDCyKD8SXMskz4Xbd5WEfkadnRZsVzHy3slQB+jE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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