SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8c0f7f54718ce2f2085430ea6e860ef7216d9d5e6ad83efcd3ca238db8d9bfc' 
  AND token = 'IFn9IannS3RMZjL7Wv47jXu9LUsiryEBTekzdGSn8t0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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