SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ecdf1a77b37611328641415c6be7709bd220f3d42b07f4805a6879f4c7e352ba' 
  AND token = 'pp6MaKCY6ghV8hDXTteGXL3Hsi/uv8n56PCKXyksNYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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