SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b3bc479fcf9603ea7f89fe9b3ecaa487190731fbb54c95a433c08629a9788f1' 
  AND token = 'as4Z4MJGbqMZhNOxoKBK+dRBofUc+8yqh+WyICe8eJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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