SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c2c4ec027585bd22059966951d1b43eb7813aa05b36c3dc99ea5c5f540c56c0b' 
  AND token = 'nXLH0y2FE7EJzzhqnHVKOie+WTFUTmQ2IK8ZIjsxsCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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