SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ab1f50b033aa7a9c8fb9b820e94ba2dda6217fd3f5e6fd34eb637ec9eac6d479' 
  AND token = 'HWgIiKe/CHTFgauObg8mgF64j6f/IjQU56FfxWp1xE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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