SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19a926cc7a01d49abbda49ed9454fb72d31e5f7b882655ba41517185157fc5ca' 
  AND token = 'CgXAnDjKcxh6zXZeV4qYNIAvF65LtIV+p+6SqKE6UI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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