SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a839cf49569cf4730d34ced7596f043124a54ab451a8d71eaad47c83ae08ac6' 
  AND token = 'ej5EV6XUUZggzzVyNGHeQR9voWirv0BqID4OpTF9YoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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