Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8247ad98688a627a4a73182585fd73c15cdc29eaaf925a6555cdaa325ddb334' 
  AND token = 'mxjE6OZC+m37cK56vwcMOAuiBqe1jufS752UpuyInFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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