SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaca40243e0e5b24b791f01cea1466d198f210e8c6454d99d2e2a4350e6538a6' 
  AND token = 'wDBxk2LrxVKHQKvQ7XoBSuHe+hvOHFVGjRqxm1ZF4tI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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