SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5a1c655a1a47ceb8999e79ae6beddccb76b146484b070ff341d589272710234' 
  AND token = 'G3S3gaox8riweOpZ1rJM9x8JTMsrqNiQPuvRbNRVt5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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