SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ca1f88b99c89a5a37498af1afd87579a73bbf13a28c2f18c66273d96874f684' 
  AND token = 'VfQiSGUNhk6iw5Gg2B+WbEhYAqVnMB2shHmqaKamUfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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