SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f601baeea77038cfdd7229a4cfc202729bb78827153876a9ae6d34afc9339cbe' 
  AND token = 'Bh6GZK0mWSFGjP949/PpqhltYh2JOjsSPW4QBeODtUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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