SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5460a4d248b73b137c4322104fc36847ea45ebbd6826bdf58419fe8f7ec8841' 
  AND token = 'msTar8LIpBi5xJNAFfZUqg6vUJP8TWvjvBgHLjGt1+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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