SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '540834e2f1808fa657f23c6d2c6a708b34bee713819915bd22c3cac90a34df87' 
  AND token = 'IcmhXnkjGUN1hmvbJFVz/4SuTeQ5h0s+kCqn0sj1Aus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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