SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f47a73b066a2fe89a423c5b587d8f4748f26f41b39a99404879ffc34e2a7ec1b' 
  AND token = '/BEKGoinO/iG/rotWp4IjBC9A53dmu7XftYXxZEJy1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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