SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffee9e72466bbff299feda8d0f94b240f81c6452b3e9b26a5aa756965c64e658' 
  AND token = '0RwgzFqAo0bvphtM0D2EO6v3BK6+aIflTUnrRlTMXek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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