SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2ab990520118a059c0c00d9786e858696579add6bc12b8e18cc027a3c33b68d2' 
  AND token = 'Nu4yBbtWbMKvvoaGho+KHh+foZPJVWy5jZzKHDqWY4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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