SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb37c7fe7e9e32bf563a6fec5941ac7c79b6249928e67759f0c9d5c65951744d' 
  AND token = 'LHU6hY6IWKLXmSFKgokKWgpvzCYVNsx89PaDAhRC4+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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