SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18f3a9f93d64c78cb2335b7ac152dadde1aba7aad362c3d0abebf321278098c2' 
  AND token = 'cbiL47MYBRan8zXYsE2iFVu44MeFbdkjONWUSjZx8WY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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