Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3b840f1417b8758f8280c0931e85b59bd8dcd1c71d0dd16cc2c51f8478fa10e4' 
  AND token = 'KlSkq1qssNd3sH4ZcTId7X0CCuy5cnnF5MTVOTUNmKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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