SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92da47510538135c20251cdf2e3ba587dcc46ab94ee8aa4baf0a1f5f192d1819' 
  AND token = 'A+YNOODgnLLZ+4YAQvqoUBYSbkKj+3JfcMrwYz0MsDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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