SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85a67b59c35d3c0701f901c323c03a7a9605c60ede0cc5d543829d7b384f2093' 
  AND token = 'YjEYE4L9zXwVoRwjGu/fJdE3fHmiKZgX+C4YHsiBPUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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