SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a157b17adf501e0314460b0a766e7bbe7f238b3bb0498fbede1ce6748044d04c' 
  AND token = 'NfIwuDUDOUjLMKpR4iGmiNYEFgoHi6YmQ6c8RiuiwsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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