SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '77476309a6b3d984f7773ee92e7fc31178da326341f5284b40e15a4998430e97' 
  AND token = 'ndQY4LmBaBvT+HN4MQgqnzSeVjGh0UjJ/XHNHyuhI44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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