SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4119d52f814e28bf164375ffc87c60b095d6a851fedc9759f75e6fb7d9b444c0' 
  AND token = 'JYVwvi3mxwsf2qUGS3zNhOiH3FTbVW6pvjayRnO9OAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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