SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44c57da55912bc7372375832e257f5ba8bfe7428a44315a7ae02fbecc394fcb7' 
  AND token = 'tp9qytHl0IMkXpo0gd1qNWzMrHB0lkLEy8bEgVxhnTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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