SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24298048ea5088cd84407470c08d0b1ac590444e72d67703b6821c75066d8b3d' 
  AND token = 'thHkrI67SycWYwOJ7qT6aliVUYXbXTeijRWraBm5uIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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