SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '61bc50f5d7480d1e6e934333bc2aaf3ac6bd86cb665e3366ae636b7d79f986df' 
  AND token = 'tRB4lNK9oECMhdjx7wqhZNUFXh5DWx7jgg4G6Y1lJpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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