SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd89b05aa382afae534c82aa50b5c7830893b19acb4dc7a2d07d11daa9612e023' 
  AND token = 'CzzzHqfAHTXJHpp2v4BM/Y63Ef7WvBJRXhcVg/CR8vU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}