SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a7ae1f93b22697878ff9ebd0c12ee8b0521d9d613816c6b674428633452b14a' 
  AND token = 'JIPsdtoCC5S8bWwDccZztqKMvUd/q8IYkjMqYK558Mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}