SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc6ac251f0a38dfaebd82c51578648016a6d6d7b3b5fdf18df8c704a90ff761a' 
  AND token = 'IaTKa4ltZB77Ye+MwPwnfGZCChy+E/sUexKUiAX5YBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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