SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6784900059861bccc462100f29e4e43d9d0dc6aca740d7e1f572bbc7672e3934' 
  AND token = 'UWzAJks+yzywZzpjfNIAsEEoQYs0MDMzJ9DSY3VLEvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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