SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8e9cc75b11df41cb7a697bb25582d5daca82f856a934ae0ae7c9b234de46b4a3' 
  AND token = 'haSHGmmdYQvwLvKno0JZcFjnt64NEr4sjoExdIU6Bmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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