SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e9b8118d4514427d5e5f0f4a267deac8940fda9cca342ec826d818454899005' 
  AND token = '6ozkFwH7kn+woSbVlcRNkRDjSerUxeU0bYS+D61okfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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