SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44c1576ee5901607dc7d44a4bc75bede8dbbd7edff929295e6adf938c8b678a' 
  AND token = 'JISAGKJpB58V6oqYPbdPwinajKaMTtYPv7YtdkZltjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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