SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71b2aba80bf210972cf2817b233615b8d5784cd34eb6d592f825bb0bd1e8b446' 
  AND token = 'N8UpH/Ob9qsH1MOLCUi9FXRSwrTnY2Ks3qlOfvleNqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00170

JSON explain

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