SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bae56d802b2dc3aae7cbdd78737780d46596f3bf84b6d5c26ec576303862ff03' 
  AND token = 'MaBrm6l2dzFJeani7ztpUel6bynAZBuefrogiDmkp/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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