SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9439943c3224281d9c674af434921c22ea81632209cbfd52d2ab115ea2c6be3f' 
  AND token = 'vy6GQQvIbw2zKlqUAHPlK/wAloArEnC7ktEol/T0SvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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