SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4b76c4435e945dee5ddb7eece8857b9dfb71299b169b2520d68a10511ceaedad' 
  AND token = 'Sd5Nt3ovjgr7tOrjerIJPmnLH5XAvKeFVv7oOOxQ0oU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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