SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '49edde4ee844315ddf2e2614c31fe84039b262852e73a31bb77317a1c8c46cdb' 
  AND token = 'kiuhEUjZ/GjNyppqPfmXREw7TmGcRctT/UmgpBh+654=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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