SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86d579259eb50089051b6a16c068a5cbc22b100ba227f5ee8c4ea10ca35ca9ab' 
  AND token = '5rkyAYQSeYMgjugRzrzpLglAE4oGHv4TD3NOTuEQo9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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