SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c8da532837b4951e829b99fc8bad470b6302bac4b9c1870d9c1fde66fa1ecf' 
  AND token = 'gK4xAnJMV3dkYqmsCK5wCOiBU95XiIaBBT4aYTAjprs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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