SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb29480959e8c4b94cffd3cb92de10359eef92c09aa9b4d5d3bc9dde8ac09406' 
  AND token = 'uVSMIYSCAj4UWNkza0xJNU2IRUgBBCfePBGh/e9vrEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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