SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bda0736fcc2480050db9d9a4268c77e0fee329a35b65bc83558864a6eb3cfef3' 
  AND token = 'CHvKQsadxvopvTQ6G47iYjJuZev9Locw6rYceGM73/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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