SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a69ef46b1f78be124ad29e1702fce8a281e84a4fcf05dbb8aa771ba92c3778e0' 
  AND token = 'Lqxjl3go/GDHYWpqsvPB65dfKsw3vxgROQEylnUz71U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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