SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47b4c082d6b78df44690b5cc703e8d528301f6eb07cad4a48a2bb03d59dcba03' 
  AND token = 'ozjpiViAje5CdYold66MbgdmK5AKsWlN8k1ZOWFIKUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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