SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5a8703a7ba895ebf652393be373c3cc5e3e6668f3d2ed82c46f4b1b6eae08e0' 
  AND token = 'It9hCzKJBz0P/JbO8Wq75sDepfRYUeER2zxrN1kyyvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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