SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5db1c251923f8eee859dd9a07502a603877068c723b9425f1cb1bc24e1237ae6' 
  AND token = 'M4ZHGag+QYIdqDf3qQGWqZV0BD6u9AtR5LyLFYvYXz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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