SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8211f59ec80c5a47e7687a4382937a0ff59545834db95e1fdafdcd3c71aae7ac' 
  AND token = 'yqxg/W9LVsefoRh8/oF0KaWG+tvtPuUjkxuzdCOIZDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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