SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf18761a8da89ca74e805e60f194cbfb2f6c0b41acbac8ce524d46f5eef0e0eb' 
  AND token = 'm6Z/1V/s6PwN7j9yU35Gi/6eH8KmnkGbd5jnyLAUA/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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