SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a7aa0cdacaa25f80b478544028cf453b121d42443a6b88deadf6aa7487268e0' 
  AND token = 'JePrW/auPR8sARQxeIfmdz8JKAcaJghJ28JleTSBKXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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