SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad0afe82acd91c5c45cd084bbb2f6f4ceb383b614d9dd1328bb9a1495904cb8e' 
  AND token = 'YFU3InuIOWI3xvQYSaDChDpLAQpWOIenAZG3fFY/Y8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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