Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '600cf0b0bc45ebe0b4d6566a7b316cc3e7ac9a8b31122ca7c53cc98dc8fe5137' 
  AND token = '1+/JUmasSOfNO5MnEIY/0nIXlGZ5p3btXFiYcpWpV/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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