SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6799e3fe2ee76691dc0d4dce7febe50fe9d963117012202e280ff85f7de9a1ad' 
  AND token = 'z6LfXwBhLX4xqCp7XE1otM2BUa/ZssWGvSlOlSo3XXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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