SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61a126ba3e842a3c6f638c34efbec296b0e96f3cef0c8d323fc4bb5ae52f890b' 
  AND token = 'ojNuWbyMIjTxCgmEZcIt04VB9xcSxXUJCv9lFYEr3qY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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