SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '702d480973fb11ae47f97a6e957439be07d22934789b72da66b955516ddd8284' 
  AND token = 'RdZM1bboZW3VJ02Pi/QkizMeKD37MWMHrTTxvpe/BKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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