SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5d565131e98668a6b1a813d0313eb357ff73c81030746ad1bc31a67b224bbab' 
  AND token = 'ws2XAqvUqtihz7Gi3XiCthXck2V3a7jLUsRvS+7bQFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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