SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b145a50e5fa81fcfd4349e445c7c9ae5d7c2b8dc47d326874d0f1fe869c82ec7' 
  AND token = 'nLwy9BQuf8hZ+kWUcGX/Homc8SoxJMxxXbhbuatyrsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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