SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15c41686f02c1236f32efea56d7c4a2b5cd5169ba660a1c4078921bc5f9cd936' 
  AND token = 'cKVX1b4JXRN/KLZuwOrcG3u2xHjyqu7LwXBxf8/Mb+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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