SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b042e87c61097f896d9a2b8898ef11dbdf6e6db9b5a14d16a58a60b9d4b45915' 
  AND token = 'KjeJjiujpjqu4Kr0yI06/llEhHbbaN9O02JFDxpdTLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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